Well I would keep the complete set together, but it is of course your choice. Is it even possible to switch the internals and have a perfect fit? I have not seen much success at doing that with original Ballards: the blocks never seem to sit correctly. I have a mismatched block and frame, I should dig them out and post the numbers in case anyone has the missing pieces. Why did people do these things? How has the Franken-Ballard parts gun worked out Froggie?