Seems all Colt magazines for the woodsman series are kind of rare and expensive. There is a tutorial at rimfirecentral on how to modify one from a Beretta Neos magazine. I made one for my 1975 huntsman that works great.
$30 for the magazine and 30 minutes work. Not as pretty as the original but functional. On the second series pistols you have to cut a slot for the mag release.
Something to think about and it might work for you.
