Jeff--I'll try to answer some of your questions.
As for the refrigerator, i believe you'll save money in the long run, if you just bite the bullet, and install a brand new one! (This from an "El Cheapo", who never buys new when it can be repaired!)
When painting aluminum, you must apply a Zinc Chromate primer to any bare aluminum, then after that dries, lightly go over it with a scuff pad, available from auto body supply stores. Then re-prime it with an automotive primer as reccommended by the auto paint store, and finish off with the color coat. Enamel works best, but you might not be able to find any, so bone up on the new finishes. Open up the many tractor sites, where they discuss tractor and auto painting. (Antique tractors/ Yesterdays tractors site has a good section on refinishing tractors, or anything else.) And, take any warnings about the effects of the new paints on your health, if sprayed!
Auto and storm window shops may have the window seals you need. And, the dum-dum putty can be bought in a large roll at a hardware store.
The roof trim, i am assuming is the kind with the screws holding it on, and then a neat plastic filler strip is squeezed into the slot, to finish it off. If that filler strip is what you need, it is available at most camping supply stores. Camping World comes to mind. It has a web site, and there's a world of info there. New screws will probably be needed, too. 5/16th head screws are the norm, an inch long.
Hope this helps! If you need any more info, e-mail me. I'll try to help!
Rustyj

jeff i have a 1972 hi lo, that i have reddone top to bottom. the ref pull it out anf juck it. there is no one that will work it. ammonia is not to be used anymore. the roof trim can be found at any rv parts place. i live in tampa. there is a place called toms rv. they will ship any place in the us. and
prices are realy cheap. the wall's, i put up house paneling from home depot much cheaper there, used liquid nail and a fisihing nail gun.the windows, go to walmart and get thing stuff call window cluak, or if is soft stuff order it from tom's. and paint i used house paint. plan white.i got it from walmart 10.00 a gal. it has been paint for a year now, and no color problems, or peeling. if you email me at vchcfr18@yahoo.com. i will send you pic's. i will help you as much as i can. Tom's Rv Center

* (813) 661-4421
hope this helps you out.
victor

Hilo are fun to redue.
Uses 1/8 paneling held by metal oval screw that have 1/8 square drive heads.Save old ones if possible.Hard as nails works ok too.
Trailer is built by strong square metal welded tubing.
Hydraulic pump can be had new one way of switch in lower cabinette left side by door.
Al pipe should be replaced .Black pipe and fittings for gas,and tubing from auto stores for the low pressure ,hydraulics system which can be ound easily on ebay as well as hydraulic 2500lb 16 inch stroke clevis threaded end cylinder..Stove can be had online.Coleman heater standup ebay or online search not recommended due to safety & room factor .My 1972 westinghouse back top wall mount AC mounted on back just died being a freon 12, and was replaced with LG heat/AC unit 7,000 BTU.Water tank by seats and pump are availabe .You can find a 30 gallon pressure by mini compressor 12 volt water tank for under seat pop up bed/table area at marinas supply ,but it is very heavy when full.Most outside covers for hose bibs are still made and available.

I have put Limo dark window film on windows excluding the pinching of curtains a real pain on sides getting caught in pulleys.$$$
ALL Lights are available except bathroom (rare) ebay jayco back Tail lights and 1 1/2 inch Bargman 100 replacements from ebay or miles trailer Florida
I have put springs on top of axle with new a saddle allowing better clearance on back dirt roads ,add 10 inch height.Tires change much better too imposible at lower height.Many loacl trailer rv service centers will do job of putting trailer above axle about 125.00 +-? Ceiling is 1/4 inch luan or finished plwood with solid vinyl white 12 ounce goods 54 inch wide,available at commercial wallpaper stores .
Can be applied with Contact cement on both side by a pro or Vinly to Vinyl wallpaper glue paste ,it has more slip and less bubble problems when sqeegy is used.
Kitchen Light covers can be had new at Miles Trailer Park in Bradenton Fl.They may not ship so pick up by friend?
Metal Bumper back 4 inch steel can be had at any welding Comany supply or trailer repair place about 100.00 8 ft section .
Fan for bath is available by searching trailer used parts places online ,sometimes Grainger has 12 volt unit to retro fit.
I have removed all old cabinet particle wood doors that were very heavy more than Oak veneer plywood 3/4 inch,use same hinges and knobs trim with router J bead. Pump Electric Cellonoid is standard ford type on Hydraulic pump and cheap at most auto stores.
Dust gasket at home depot beaded rubber edge or online rubber flat 1 1/4 inch by 1/8 held by flat aluminum and self tap philips screws.
Most Uhaul will repair electric harness change bulbs if on hand to match unit of car cabability especially on a new car(caution as it may be monitored by built in security system and blow out,ouch .
Tires are available everywhere 225 75 14 about 80-100 dollars.I got mine at Tire Kingdom and they had originals available . Door gaskets and felts from a large window door factory slide right in .
Door latches and locks a real pain to find original but not impossible . Be care full not to use standard lock set it will break off when lowering unit breaking and may damage unit walls.Original with small lever handle inside and lockset outside.I also have put a nice hasp set as back up security as lockset is easily hammered off.

Put lexan inside entrace door bottom to beef up white tin.(safety feature) remove screws and place 3/16 lexan or aluminum and replace back trim ,hold it in with same metal screws taken out ,otherwise you will soon put foot right thru the bottom or a uninvited visitor will?

Have a fun time.