Why don't you keep it simple.....just slot the holes in the perches for the locating pins, slide it over and tighten her down? Or oversize the holes and use an offset bushing?
That's what I did. You can easily get it to move 1/4" to 3/8" by using a die grinder to slot out the perch hole.
If you need more then you can use a 1/8" or 3/16" spacer between the rim and the axle. You can't put too much between the rim and the axle unless you have really long studs.
Treblig
