maddoc
... likes film again.
Peter, Thank you very much for your helpful tip. Indeed, I had exactly that eye piece magnifier about 12 or 13 yrs ago when I started out with Leica. That is also when I first met the owner of the shop, Japan Exposures, who became a friend. The problem is that due the magnification and increased distance of the eye to the VF the 28mm frame lines are impossible to see and 35 only very hard. However, I just searched eBay and found a seller from China who sells similar principle eye piece with variable magnification starting from 1.0x. I will test one and see if this works for me.
Maddoc if your eyesight is changing you could try
what I use. Japan Exposures Store, markets an "eye piece magnifier" for Leica M in various magnifications (0.85x' 1.15x and 1.35x) but the real advantage is that they all include steplessly variable diopters between -3 and +1) Due to some licensing considerations they put in a disclaimer saying its not intended for use on Leicas in USA but in reality how it is used is up to the buyer. Works pretty well I find especially as my eyes are degrading too and its much more convenient than Leica's fixed diopters. They are not exactly cheap but still affordable if you need it and well worth the money I think
The only one available right now is the 1.35x (others are sold out.)
https://www.japanexposures.com/shop/accessories/ms-mag-x1.35-magnifier-for-leica-m.html
EDIT: I just noticed they now even sell a 1.8x magnifier for Leica M. That's new. And possibly useful for people like me who like using longer lenses.
https://www.japanexposures.com/shop/accessories/ms-mag-x1.8-magnifier-for-leica-m.html