Unfortunately, I doubt many will see your post in this obscure photo sub-forum. Also, I am a little uncertain about some wording in your post, but I think I understand the general idea. Trees can often cover over their wounds if they are growing vigorously and are in good health. You mentioned that your tree has been "pruned to be very sparse". That sounds like you are making it much harder for the tree to successfully recover. Starving the tree of food by limiting it's foliage and forcing it to overcome pruning wounds would certainly present obstacles to the tree's recovery. It is unlikely that removing a section of trunk would be the way to go. A bridge graft might help, but is probably not worth the trouble. Again, what you need to do is to increase the tree's vigor, and the best way to do that might be to leave it alone for a while! And, yes, the plaster cast is a crazy (bad) idea.

I can't seem to locate any granite chips at lowes or home depot. Will be checking out a feed store tonite. There's this from a landscaping store nearby. Will it work? http://www.vistalandscape.com/images/RGC.jpg

There's a major mis-step in the process... Prior to doing the carpentry, the leaves on the scion need to be clipped off leaving about 1/4 - 1/2 inch of petiole. The understock can either keep its leaves or really it doesn't matter. It's common to chop a 3 foot tall understock down to one foot where no leaves are and graft your scion right to that. No problem there. It's more than ok to chop the understock way down so it isn't tall as well. The plants may be sealed with all of the above mentioned materials. (parafilm, bud stip, rubber band) The grafted plants need to be placed under a large tree so they receive minimal light. Perfect conditions are dappled light. Or you need to create this type of an environment. A camping tent will do the same work in a barn for example. The graft will only be successful if the petioles turn black, then fall off to expose a healthy bud that has pushed from below the petiole. Actually, summer grafting is 100% less work due to time involved. The new graft should be known to have been a success in approximately 10-14 days give or take a week. Also, do not water the understock prior to grafting. You want it almost dry but just a bit moist. Too much water and you have a dead scion. After the graft shows success, place it in full shade for the next two full years. And... when you place it into shade, give it one week of keeping the understock almost bone-dry again, but giving it just enough water to not allow it to die. This is MAJOR. After that week, you can water it as often as you like. Heavy amounts of water won't do any harm. You still won't know if the graft is successfull until the following spring. Careful overwintering surely plays its part in the process. Don't go over 50 degrees F and you'll have given them enough cold for any dormancy requirements. Grafting ends about August the first for Maples. (Mid July - Beginning of August) You can also graft Ginkgo the same above-mentioned way. Ginkgo has a longer time-frame allowing grafting to continue into September first. Here's a photo of some summer maple grafts... Dax

I agree with both garden gal and t charles ...I don't think it would have survived that long (50+ years) under such BAD treatment...the whole thing makes little sense ..it just couldn't be that badly stunted ( IE: small caliper trunk )and uncared for and be 50+ years old IMHO...But the trouble involved to dig it up even if it's 1/3 that age is too much for 100 bucks ..Tcharles idea is perfect... spend the time to containerize it and try to make something of it ...it may never be worth more than $100 but you could eventually have a nice tree ...in it's current condition I wouldn't personally pay 10$$ for it....it is pitiful ....David