They're pretty ugly but the usual method is to use what we always called flex gripper metal. http://www.hardwareharbor.com/Carpet-Grip-Flex-72-Mill-By-M-D-Building-Products_p_16755.html When we installed lots of vinyl I guess people were able to actually get their foot over a 3/4" height transition without kiliing themselves. If you really want to raise the height of the vinyl hire a contractor that will add a layer of plywood. Since it's over concrete you should have a moisture barrier between the concrete and plywood. Or you could float the entire vinyl floor area with something like Ardex K15 but it can get expensive. We now do mostly wood floors now but I do the occasional vinyl and it's ideal for many people.

If you are worried, send a sample to a reputable lab to be tested. It runs $25 - $50 and you'll have the results in 1-3 days. Although asbestos backing on vinyl flooring was outlawed, some shady flooring retailers were still installing it after 1984. We found that out just before we removed flooring from our kitchen!

THis is just a summer cottage, no insulation, heat, etc. it was built by a farmer for my parents 50 + years ago. The pine floors aren’t even tongue & groove, just very irregular boards, and I have no interest whatsoever in the time or expense of refinishing them. The vinyl plank is purchased; my only question is about the type of thrasition to orde.

@acm right - not the same hardwood. we're trying a DIY project and not sure of the direction. If you have any better ideas, I'd be happy to hear!! Also, could you please show me an example of slate-look you mentioned! Thanks so much