Barrel Mounted Rapid Rectilinear ID Help and Cleaning Advice?

[Punkinhed7]

Picked up this lens off that big auction site not really knowing what I was getting --bad pictures, but it looked interesting. The lens is mounted in a 2.75-3' square lens board and has a diameter of ~1 inch.

The barrel is marked " Eastman Kodak CO. Rochester N.Y. USA" then has an aperture scale from 4 - 64. No visible markings on the front element and back element says it's a Bausch & Lomb Optical Rapid Rectilinear. Has 15 blade iris and focal length appears to be ~6 inches. No problem covering 4x5 at infinity.

I'm assuming it's a B&L-made RR from an Old Kodak but the barrel mount kinda throws me and I'm not finding much on f/4 RRs.

So, if anyone has any ideas re: the original camera this may have been on (or enlarger?), whether that might have used this lens board, if it's actually the front/rear elements from two different lenses, or any other explanations, etc., I'd love to hear em.

On another note, the thing is pretty dirty with what I'm pretty sure is some (quite a bit) of fungus and the blades are pretty grimy (though still adjust smoothly). I'm planning to try and clean it up a bit but am a little unsure as to how to proceed as this will be my first time cleaning an un-coated (I'm assuming?) lens or one quite so dirty...but at least it's easy to open!
Any tips/tricks/advice for this would be greatly appreciated as well.

Thanks.

[Punkinhed7]

one more pic

[Jim Noel]

Measure the FL and the diameter of the open diaphragm to determine f stop. It may be US 4, not f-4.

[Louis Pacilla]

Unscrew the cells clean & treat them the same way you clean and treat any optical system & your good to go.

It's a US system & not "f" stops. So f4 in US system is f8 in "f" stop system. I will add an attachment so take a look.

No offense meant but it's a run of the mill late RR and dose not appear to be a long FL. Not valuable & hope you did not pay much for it. If your just wanting to play around with it on 4x5 it will probably preform as well as a RR in this size would and that's not bad. sharp stopped down a bit w/ nice contrast for a non coated lens. Mostly because of a simple design w/ only 4 air to glass surfaces.

[Punkinhed7]

Thanks for the info guys. @Louis, why would I take offense? I didn't really know what I was getting (and didn't pay too much) when I bought it and didn't get it for the monetary value besides. As I said, the focal length appears to be ~6 inches. The only thing I'm slightly disappointed about is that it appeared slightly larger in the photos and I was hoping that I could fit one of the new(old) packard shutters I just picked up onto the front. Oh well.

I'm still curious as to it's origins re: the barrel mount and lens board though if anyone has any ideas.

Also, forgive my ignorance, but what would be your advice on the best materials to use for cleaning it?

[winterclock]

It appears to be from a Graflex homeportrait or auto slr. The board is the same size as the one in my3 1/4 x4 1/4, the focal length is also similar. The camera has a curtain shutter so doea not need an in lens shutter.