cant say what it is exactly, but theres four threaded holes underneath, about 5"x 3" or so square pattern at M8... for the footpegs but works to hold em down just as well.
and the two "standard" mounts, one at rear, one on top of case. just need some plates cut and drilled to suit then welded to something.. quite simple.
1p52...actually a 120cc... about 420mm tip to tail. 50,70,90 etc about the same.
1p54... genuine 125cc, big valve head... about 450.
1p55, the 140... about 480mm.
140 have far superior clutches
start in gear etc...
some have an electric starter on top. some stick it below. some forget about the thing altogether... it gets in the way.
i had one that forgot about the kick starter and the gear shift besides. and one with reverse...good for a trike...