I have a couple of Comoys with pearlescent stems (and an Iwan Ries stamped bulldog that I am 90% positive is also a Comoy). They can usually be found on the Bay for pretty cheap (I think the most expensive was the IR shop pipe, which cost me a lordly $7).
If you are having trouble finding a pipe featuring a pearlescent stem off of the rack, perhaps you could approach one of the refurbishers such as
Walker Briar Works and have something custom made for you?