I just reread your first post and saw you cleaned with brake cleaner which is acetone I believe. If that did not make the inserts a bit tacky, then you are left with adding rosin, glue of some sort, or electrical tape to the undersides of the inserts. I have used high quality electrical tape with good results for many years. Others, as stated, use rosin with good results. That added to the inserts should be secure and safe to the scope finish.
