Do these exist anywhere? I have a couple of Kotobukiya bazookas that I originally purchased for my MP carbots that I would like to use as shoulder cannons for Titans Return Sentinel Prime. The pistol grip on these cannons plugs in via a 3mm peg, so I'd need a male 5mm peg/male 3mm peg. I have found these double 5mm ones on Shapeways but those aren't specifically what I needed.
Well if you don't mind that you can't quickly undo it, the ghetto way is to wrap ordinary tape around the peg until it's the right size. A more reversible way is to stuff a layer or two of napkin into the socket (pushed in with your peg) until it fits snugly.
I'm not certain, since it's been a long time since I had them but I believe that the early Zoids Blox and Z-Builders had an such an adapter in the sets. I really need to figure out what I did with those, a Blox unit could easily substitute in for a custom all spark cube.
