The catch is not a problem, but extensive diassembly is required to take a photgraph of the follower. If you check online at Numrich Gun Parts Corp. I believe they have diagrams of various firearms, and may have a picture of the follower there.
If not, send me an email, and I'll try to see if I can get a picture of the folower on one of my 1897's or '97's. marlinguy@juno.com
If you can't get the tube and catch working, the complete 39a tube assembly, inner and outer, plus the bezel to fit the dovetail on the barrel can be purchased from Wisners or Brownells. These can be easily mounted on a model 1897 or '97, and will function fine with the earlier rifles.
Any problems, drop me a email, as I done this conversion for others before.