Stems with screw style tenons

[matchstickman]

I recently got a pipe off ebay for dirt cheap but I dont think that I can save the stem. I need a new one but the old assembly is one of those aluminum screw type tenons that threads into an aluminum part on the shank. Anyone know if/where I can buy one of these stems?

 

[unclearthur]

As far as I know no one is selling that type of stem. Many repair shops can take your old aluminum parts and instal them on a new stem.