i asked PPI and thisis what they quoted me....Seems as price jumped almost triple.
One new "R" power steering cooler remaining in stock... $99.99
One exceptionally nice used "R" oil cooler in stock... $249.99
One new "R" oil cooler in stock... $399.99
I'm not aware of any other vendors that really have a "niche" in stocking/selling those types of hard to find parts. You could try asking several dealerships near you or keep your eyes peeled on the many classified sections of mustang message boards out there on the 'net...g'luck.
Got the "R" oil cooler and steering cooler, Thermo sandwich plate and 10an lines from a guy in GA for $140 bucks shipped, Arrived yesterday, It looks almost new and does not leak, I got lucky BUT when i need to replace this thing it's gonna be pain in the butt, I am changing the rubber lines with these braided ones with an fittings he gave me, Don't need the thermo plate so if anyone needs it let me know, It's Earl's 510ERL. When you add oil cooler on your car you will need this, It already has oil temp sensor drilled and tapped in to the adapter, Cool little thing.