Quote Originally Posted by johnnywalker View Post
I use a small saw blade for an I (1), a small triangular file for the V (5) and a round file (like a power saw file) for a U (10). I mark the wooden or plastic flap the dark slide slides into, and the marks come out on the edge of the film (if I loaded it properly). So UVII would be number 17.
Brilliant!!

Thanks for that ... (rattling sound as Kent rifles through tool box looking for kit with variously shaped little files ...).