P 67 finder questions

I have a p67 with non metered prism. There is what looks like some de silvering going on, right smack in the center where it bugs me.
I was looking at KEH for a replacement, and there are a bunch of different metered models. I would just as soon get a meter, but have no idea what the differences in the models are. Can someone steer me in the right direction?
Also, is it possible to get diopters for the finders?

You don't have the 67 II do you? I think you have only two prisms to choose from. Metered and non metered. And as cheap as the non metered ones go on ebay I would buy it there. Or get the metered version which will cost quite a bit more. I bought a perfectly mint condition non metered prism off ebay for under 50 USD.
Dennis

Does not sound like the later model Pentax 67II.

You have 3 options: a basic prism finder (the same as you have), a pop-up waist level finder with the image upside down and reversed, or a metered finder. The metered finder is the general averaging type, nothing fancy. I am not sure, but it might include an aperture preferred automatic mode. No diopter correction is available.

The newer Pentax 67II is much more sophisticated and include a metered prism with diopter correction. It includes general averaging mode, matrix metering, spot metering, exposure compensation, multiple exposure mode, etc. It is much more expensive though.

I have both and of course prefer the 67II. With the older 67 MLU I use a Gossen Luna Pro SBC meter with the 5 degree spot attachment.

Actually the diopter is available. I bought a +1 new at a camera store. The new verison prisms must have the same size eye piece as the old. I think I had to pay something like 17 dollars for it.

There are a couple different versions of the metered prisms, mostly it has to do with either a permanent on/off switch (which you will accidently leave on and drain the battery) and a push on switch which just switches on the meter for 30 seconds or so. The meter with the push on switch is better but it's not an essiential. Also don't worry much if it says "NO RING", I use my TTL Prism without a ring, it makes changing shutter speeds a little harder but it works fine.

Thank you all.