New Old Stock NOS - a good idea ?

What kind of seal material is it? If it's leather it should be replaced. Buna-N might be ok depending on how the part was preserved (cosmoline wrap). It it's graphite packing they last forever.

I can probably find the material composition for the seal as it's made TODAY, but that same number many years ago could quite possibly have been made from something else - I would think.

It's some type of double lip "rubber" (layman here) seal encased in a metal sleeve.

I'll call the supplier with the new old stock pump and ask about how it was or was not preserved.

You gave me an idea Mr. Magnet... What about replacing the "modern seal" (which is overpriced/ unavailable) with packing ? I could cap the top of the cavity with a small washer etc.

What packing material would be best for diesel?

Thanks

There is an art to properly packing a pump and generally requires a packing gland that can be tightened, sometimes by spring loading. Graphite impregnated packing is what Cat used for early transfer pump seals and is recommended for diesel. That said I know of emergency repairs done with graphite string packing available and most any plumbing supply source. Just not the best to use. Hard to believe you can't find an interchange for a conventional lip type seal

Do you have a picture and/or parts diagram for this pump? In some cases the housing can be re-machined to accept a different and more common seal or seals.

Of course it's a crapshoot, but it may be worth it, since the seal is too rich for your blood that may be the only way out...did you ever take the seal to a seal/bearing place to see if they could cross it over? If the seal in the NOS pump is dried up you may be facing the same thing. I looked on redpower, & the 266594R91 seems to be the one you need. i found one for $70, if that's any better than what you found. Case IH makes both Cat & JD look like K-Mart with some of their prices on old stuff...