I've got a Model M that has quite a few of the weld spots fallen off. Fortunately, there're still enough in place so it feels quite solid and there isn't a gap when it's at rest. I'm planning a bolt mod but don't really want to disassemble all the layers if I don't have to. Thinking that I can drill through using the metal plate's hole as a guide and be very careful not to break through the plastic in between the layers - so there won't be plastic loose bits inside. After all the posts without weld spots have been replaced with bolts, then the remaining welds will be scraped off one at a time and will get bolts as well.
Does this sound like a workable plan? Anyone else tried this approach?