U.S. Ordnance proposed change of M1921 barrel to M1928 - photo from National Archives

[TD.]

Yes, I do have Gordon's 6th and final edition 2 volume set. 

I think we have beat this subject to death. You are welcome to believe what you want. While NO 15025 may have been prepared as part of the Swedish contract, it did not ship to Sweden. One reason I spent so much time developing the Swedish Colt's story was to see if I could find any 15,000 numbered Colt's in the Swedish 500 gun order. Unfortunately, no serial number lists were uncovered but it was still a very good story that has paid dividends in other areas of research. 

I have not found an owner of a Colt Thompson that would allow the removal of the compensator just to check for the threads or a second pin grove. If you know someone that will allow this, please pass this information along to me.

If I do another story on a Colt Thompson with a "H" marked barrel, I will certainly identify the maker. 

All good stuff!!!