Heard back from P&C
...it appears the design was changed when production was moved to Italy. Unfortunately, the rep says all their Army Mount pipes now use the design you received. You will not be able to get a new Stanwell pipe with the traditional army mount stem you seek. If you are stuck on a Stanwell pipe your only hope is to look for an older Estate Stanwell.
D'oh!!!

Well P&C is good about taking returns - they send a prepaid label and all that. I still hate returning stuff tho.
Guess I'll peruse their site for a Pete...