Order the scale plans catalog from Bob Holman. Its mostly copies of a bunch of catalogs. When I got mine, it was like reading a good book. Couldnt put it down for months. There are lots of 75" and 80" sized planes in there. And tons of plans that are not listed on the web site. I have a Holman (actually a Brian Taylor) 75" corsair mostly built that I got from a swap meet last year. Its very light with a glass fuse. The wings were'nt built with flaps so I'll definately change that and strip the moneykote off of it and glass it. Shindin machine will make a set of custom retracts for it. Power plant is stated to be from 1.50 to 1.80 4 stroke but I will try a ryobi 31 gasser since the cowl was already cut for a G-38. I'm sure he'll have something in the size you're looking for. I consider that catalog a gold mine amoungst all my other catalogs.
Edwin