Hello;
I know it sounds strange both Brazilian xchanging messages in English, but I believe you understand my point, "certo?"
I also have an old 41CV (1985) that also needs some batteries 'shaking' before turning on. I achieved some better results by soldering two small, thin metal pieces over the contacts (please, don't blame me... the original were about to vanish). I also use commercial metal polisher (in Brazil we have Brasso and Silvo) that chemically clean contacts. After cleanning them, I use micro oil (Tutti, or WD40) with a swab or brush, just to place a protective cover.
I had once to open this caculator, carefully clean the mainboard contacts, use the procedure above and it worked fine for more than 2 years. It is working again (after about 7 years stored) and the contacts were cleaned, ready to work.
If you need something else, feel free e-mailing me.
Cheers from Minas Gerais (treim bão, sô!)
(Kind of That´s good stuff in my place...)