I see a 4 inch smoke discharger for sale over on gun nutz. Not cheap....asking price is $1995, but is is complete with the barrel nut, which seems to be the hardest part to find on these things. Most of the remaining parts can be had occasionally....the 4" tube and the shortened stock are both availbale in the US from Springfield sporters. Import to Canada is controlled however and in the same breath, Springfield no longer exports.
Again, a lot to pay, but if you gotta have one, and have more money than time, at least it is available. I had loaned the discharger nut to a few people to have a copy made, and both times it took several months and I believe it ran close to $200 to make.
You will need to register on gunnutz to see this link:
http://www.canadiangunnutz.com/forum...-and-43-Mauser
Anyway, here is a shot of the launcher that is listed over on gunnutz: