Contact Jon Goodman - interslice on eBay. He sells adapters that take the 675 hearing aid cells but fit the battery compartments.
I've bought a few things from him - he is great to deal with.
He is most famous for light seal kits for older cameras.
His email address can be obtained by clicking on the link at the bottom of his eBay listings.
The wein cells do work, but are expensive.