[2bits]

I was just given a nice Polaroid 850 by my brother. He was cleaning out a storage shed on his farm, and ran across it. It seems to be in great condition, bellows are light tight, the covering is in good shape.Shutter works fine. The PX 13 battery was a little corroded, so I will clean the compartment out good. But it was the old Polaroid roll film camera.
Does anyone know the size lens on these monsters? And if you were to mod for modern film what route would you take? I've seen that some go for 120 film 6X6, and others to 4X5. The inside back measurement is about 8X10cm, so I guess there are really several ways to approach this?
I'm aware they are big and clunky etc and some may ask should you bother?
But I see it as potentially a fun project.
Any response on this will be greatly appreciated.
2bits