First or Second Series? There's 2 different body styles for '55. The early version is a carryover from '54, the late one is the same as '56-'59.
I've bought parts from pretty much all of the parts suppliers, never had to much trouble exept for 1 time with Golden State (slow with getting the parts to me) and once with Classic Parts (not their fault, manufacturer discontinued the part).
The Filling Station is in Lebanon Or., not sure how close that is to Portland. I've got parts from them before, good service. You might check out the others listed on the Links page. Many of them offer discounts and special offers like free shipping to Stovebolt members.