824tsv,I also remember 9x23 Conversion Units (top ends). I've never seen one in person, only pic's.
During the 7 year period before the lawsuit between Colt and the originator of the 9 X 23 was settled, the IPSC dropped the power factor to 165, basically obsoleting the 9 X 23.A co worker/ friend of mine offered to give me his 38 super brass ( which I download to fire in my 1903 pocket hammer colt) because with the latest powders available to reloaders, 9x19 is able to make major power levels. So the usefulness of these designs has a limited market. I have limited experience with that type of shooting but some of those tuned race guns are pure pleasure to shoot.