Just to let some of your guys know. I found a place in Canada called Memory Express that sells 10oz cans of duster. Priced at 10$, they have local stores mostly on the west side of canada.
Here's a link.
http://www.memoryexpress.com/Products/MX24944
I know this forum is inactive but just adding in what I found out.
For me and TM pistols, after the basic upgrades. TM mags still work with propane, make sure you keep them lubbed and all that jazz.
Hope this helps