my approach for the modding is somewhat different from the modding projects here.
Instead of removing existing apple standoffs on the casing then using epoxy to fix and align them to comply with atx/matx motherboard mounting holes, I've been trying to make an adapter board that has mounting holes from BOTH mac pro and atx.
with this board, there is no need to remove existing apple standoffs then realigning them to fit atx specs. the only thing left to do is to trim the height of the existing standoffs and mount atx standoffs on the same board.
The question is, would this be a better solution than the current way of doing things? (of course, if you have spare logic boards, we can discuss further)
I've attached a diagram to illustrate the concept.
Note: this is not a interest check for a mass order of a commercial product, just a discussion.