I wouldn't know for sure, but I'd suspect an insert would be marginal for remaining strength after some slick machining, and very difficult to package an auxiliary extractor that is activated by the original. If you think you can do the machining, maybe you could make a simple form die to convert 38 spec brass base on a chamber cast, and seat bullets with a shorter 32 pistol die even if it's a bit oversized.
You don't have to thread it for a press, and it may be a bit better to size down to the rim and tap out with a dowel. After fireforming, I doubt you would have to size again, but you could probably figure out a combo of neck sizing and universal expander/flaring die if needed. Hope you get it shooting.
