There's an endless array of things we can try with No. 1's.
Ray's suggestion is a good one. All I casn say is that in any pre-1990 No. 1 that gave me and problem, a Hicks Accurizer fixed it, which is functionally very much like what Ray describes.
For those who haven't used one, the Hicks thingy is easy to install and makes experimenting with different forend tension extremely easy.
