Changing mechs on scorp 4 and 5?

I'm helping a mate op change his machines to new coin, it seems the 126DFX are easier to do, but some of the machines have 435A and SR5, so question is can a 126DFX be fitted where these mechs were without any issues?

Also some of the 126DFX have a square plug that plugs in opposite side from where the sorter plugs in underneath the mech, are all 126DFX compatible with either plug?

Thanks Ronnie