My stem type? And how to fix this loose stem?

[deathmetal]

Is your stem a grower or a shower?

 

[sasquatch]

"Looks to me like this pipe was made with what is called a reverse tenon. The tenon is in the shank instead of the stem. Carey made pipes like this as did others. Some pipe makers will use a reverse tenon in a bamboo shanked pipe.

If the aluminum tenon on this pipe was supposed to be glued into the stem it would most likely be knurled or grooved which would help make sure it stayed in the stem."
This. You have a reverse-tenon setup is all.