Yep, bear with me, I'll dig them out and update this post with the measurements I used.
UPDATE:
Ok, steel used; 4 x 530mm lengths of 50mm x 25mm x 2.5mm rectangular section steel. I bought slightly longer so I could neaten/square off any rough cuts left by the supplier then end up with 520mm for each of the 4 rails.
The Van seat bolt pattern (between mounting bolt centres); 397mm wide by 383mm long, by my measurements (I have seen swivel manufactures list the pattern as 398 x 384). Uses M8 fixings.
MK7 Golf R seat bolt pattern; 475mm wide by 365mm long. Uses M10 fixings.
This means the van seat pattern is 18mm longer and 78mm narrower than the Golf seat. The Golf seats also sit lower than standard van seats hence why I used 25mm high steel section for the mock up.
Hopefully this extremely technical and high-quality engineering drawing.......created on paint
should demonstrate the way I offset the Golf seat relative to the van seat position in order to get it to sit central.
View attachment 37436
I simply created a mirror image of the above layout for the drivers side.