Drop bars and cantis are like toast and butter, they will work fine although you may have to play with the stem to get the fit dialled in.

MTB geometry is often a little different than road and track bikes which are usually square, a 22 inch top tube probably means the frame is a 20 which puts it into the medium size range.

Think the stock crank is a Sugino 250 which is pretty low end and not suitable for singulation and of those are vertical dropouts you will need to use a tensioner which is a good use for the old rear d.

Check the wheels for true and proper spoke tension, make sure the frame is straight (and it does look pretty clean) and if that all checks out, go to town on it.