As a last resort you might contact a place in Tulsa, Ok that makes all kinds of seals and don't have a minimum charge if you can deal with them without doing invoices, and paper work.
You might have to mail them the old seals so as they can do a match.
The name of the company is Crown Products Inc You can get contact info at this link.
http://www.crownproductsinc.com/They have been in the same location for 40 years. (they make all kinds of gaskets, seals, orings of all sizes and types.
When I need old obselete hydraulic jack seals, water pump seals, odd size o rings I take my old show and tell stuff to their counter and usually immediately get the correct parts, but every once in awhile they have to order a odd seal from their warehouse then ship to me and they just throw the part in a envelope and mail usps instead of a $6 ups or fed ex charge.
They have some good info on their website about seals/orings of different material types, etc.
You may have to invest in a phone call to a counter person (they do industrial sales) so try to stay with a counter employee to dodge a minimum charge Industrial sales dept.
I tried to email them awhile back and no go and had to call them by phone. (email would not fly????)I've rebuilt hydraulic cylinders, jacks, water pumps, o/rings for gaskets, etc and most generally come out with a sack full of seals for just a few dollars.
They do not go by manufacturer equipment model numbers for obsolete seals stuff they just match up the old stuff by matching the old seals or the bore and shaft sizes, etc. (OD X ID x Diameter , etc.