This one worked! 120 film in 8x10 holder.
Scotch tape seemed to stick more to me than the film, so this was held down by little sticky labels. Had to use quite a few. Sticking just the ends had the film coming loose. You can see where the labels were. Any suggestions on better ways to stick curly film to metal, in the dark?
Have used the double sided tape in a couple of film holders. Definitely easier than what I did before. Now I just have to expose the film. I'll let you know if it comes unstuck during exposure, gets caught by the darkslide and pulled off, or works out beautifully.