It has taken me a few weeks, but I'm almost ready to take pictures. Intrepid 5x4 Black Edition with Nikkor 210 5.6. The lens came with a board that was too thick for the camera, so I got Intrepid to send me a suitable board. The ring was too tight to remove on the original board, so I had to source a double screw-driver for that. Worked like a dream. The lens is on, everything seems to move as it should.
I have a Calumet Medium-Format holder for my first shots - cheaper when making mistakes - and Toyo holders for when I move on to sheet film.
What I don't have is a dark cloth and a loupe. Advice on both warmly received, thank you.