Beetle IRS trailing arms - are there different types???

[moggy]

A friend of mine has run into problems on his buggy project and it's got both me and him both stumped.

Is it possible to get trailing arms for a type one that are different?
I have just replaced some (long story).

I noticed that one of the arms had much thicker metal for the shock mount. When I fitted all the bearings, spacers etc (from the original ones) one of the disk calipers is approx 1mm too close to the disk. I took it apart to check and evertything is the same both sides (spacers, bearings etc).

Could the trailing arms have different positions for the bearings?
(all bearings are fully home - the disk is too far in towards the middle of the car)