Hello, I have used HPs since my first HP35 (1974ish) and on through the 19BII and 28S. I recently reverted to my 41C because of whatever.
I discovered this Web site by accident. I might go through the old 41 boxes (manuals, card reader, various modules) to see if there are any needed things.
It has been fun reading through some of the postings.
I still have my slide rules, too.
John M.