[Flojo]

well, technically there is no problem to fix a thin flange SSI when you have long bolts.
The other way round would be no good without changing the bolts.

only problem you might face is that the stock barrel nuts wont set up full way as the bolt will show up in the center an you wont grip the nut anymore.
the idea of using wahsers (up to 5mm) is not so state of the art.
so better think of regular 6-edge copper nuts...