Frank, keep asking.
When I bought my first, a TC Renegade, about 35 years ago, I knew no one else with a frontstuffer. I asked around, at finally a fellow at the shop where I bought the gun told me of a group called the Mount Baker Long Rifles, but he didn't have any contact names. I kept up the search. One Friday as I was driving home from work, I came up behind a small motorhome with a rear mounted spare with a cover that had a painting of the mountain, crossed longrifles, and "MBLR" written across the bottom. I knew I had my connection, and resolved to follow him as far as need be to talk to him. A few miles further he pulled into a country grocery's parking lot, and I had him! I got an immediate invitation to join them in a weekend shoot that it turned out was about a 10 minute drive from my house. I shot with those guys for years, until my job took me away. They are still there, small and unknown, shooting once a month. Somewhere out there is a club like them for you.
Since you are in SW Washington, I'd head for Fort Vancouver or Fort Clatsop, and ask the folks there. You'll find them, I know you will.