I've Got This Old...And I Read That...
Ah. Ah, indeed.
I too have got these old...'s and have been reading that you can get an ... to attach them to the ... and then you can...until you fall down dizzy. Or you can save time by falling down dizzy to start with.
The widespread adaptation of the CNC machine in small workshops in northern Asia has facilitated this no end. We can get adapters to stick nearly anything to nearly anything else. Sometimes it seems a good idea and sometimes it just seems an idea. Fortunately most of these devices are fairly inexpensive so that if the advice from the internet proves rotten you can throw them away with little regret.
It's no that they are bad products - indeed they are very well made. The stumbling block is what you might be trying to do with what goes on the front...reusing old lenses sometimes yields marginal results. Camera lenses that might have yielded a sort of a negative or slide on the old 1959 SLR might be woeful with the mirror-less sensor on the latest camera. There can even be compounds of misery - lenses that were intended to be universal optics with complex adapters in the film era clapped onto a digital adapter and waved in the breeze...Oh Dear...
I proved this to myself at an event when I tried to adapt a tele/macro/zoom lens to my mirror-less and got a day's-worth of slightly fuzzy images. Focusing issues? ser shake issues? Dodgy aperture setting? All three? Well, I learned and I paid and it won't be until the same event next year that I can recover those images I need.
Contrast this with a similar event a fortnight ago - same camera, same flash, but with a purpose-built zoom lens from the manufacturer of the camera dedicated to the camera mount. No fuzzies. Clean results. Easy operation. Best purchase decision I have made in a long time.
Please feel free to imagine and experiment - but be prepared to set fire to your shirt when some of the experiments go wrong.