pacomb,
You have shown, once again, how lucky we are to have Second Amendment protections. It is absolutely silly for your leaders to think a project such as yours would ever be used in any illegal way. Really, if you can find a double gun with a Deeley latch, it would not be beyond your capability to take it apart and copy it part by part. I have had them apart and the pieces are not especially complicated, with only one needing hardening and you can purchase the spring and screws you need from common sources. This would be easier than converting a "normal" one with push rod to a Deeley type.
Mike
