It's not in Philadelphia, but just outside of it.
4038 Skippack Pike, Skippack, PA 19474-0466 (Sharp Unique Gifts For Men)
I was actually there today. One of the nicest guys I have ever met. He showed me some amazing knives, both custom and production. He has a great selection of CRK's, even some pretty rare ones.
He showed me some of his custom stuff, and I got to handle a f@cking beautiful Warren Osbourne custom. I was simply flabbergasted at the intricate detail. I also got to fondle a Ron Lake.
On the more affordable end, he has a decent selection of BM's and Spydercos.