Can't help you in UK....
Can't help you in UK....
But in the USA, all my Fuji's (big and small rangefinders) go to Frank Marshman at CameraWiz in Harrisonburg, Va.
1-800-471-8133
He's put bellows in the GS645 (2) for me, and worked on GS645S and G690 and others.
He's been good to me.
He's timely... only cameras that took long were getting bellows for the GS645 folder.
He's a good on the phone and not so much by e-mail. All my conversations with him have been helpful. He has no problem getting parts from Fuji... last job was a back LCD on a GA645Zi. Back in a week plus, and I'm on the Pacific Coast, he's on the East Coast.
He's very reasonable.
If you're willing to ship, you probably won't find anyone who's had more experience with these Fuji rangefinders, outside of Fuji.
It's a nice camera. I've had 4 of them... very user friendly and very sharp lens.