HI Steve..
as for the standoffs i used light ply 1/8" and traced the backplate onto it..then i cut out the ply stacked 3 on top of each other then drilled out the holes for th mounting bolts mounted the standoff and the engine to the fire wall worked out great ... as for the tail wheel the one on the kange it week so i did replace it .. the cg ended up right on i used 2 1800 mill batt. packs hope this helps

rob