OK I'm gonna talk to myself one more time here and let you all know this had a happy ending...

After finding phone # for the seller on their Ebay page, I called them, explained I accidentally ordered the wrong grade, but could I upgrade to the correct/better Grade 1 oil for flat tappet engines and pay the difference? NO PROBLEM! The helful man on the phone immediately refunded my err'd Ebay purchase, sent me an invoice for the proper oil that I intended to buy, and I promptly paid him. End price was still extremely competitive at about $6.70/quart including shipping to my door.

So...if ANYONE is seeking a Brad Penn oil dealer who sells for competitive prices, contact these fine folks...and if you want even a slightly better deal, just pick up the phone and order that way instead of thru Ebay, and they'll take a couple bucks off the listed Ebay price due to skipping Ebay's excessive fees...

Here's their Ebay store:
http://stores.ebay.com/Specialized-Power...d=p4634.c0.m322

And if anyone is wondering, what the heck is Brad Penn Grade 1 oil? It's specifically recommended by Rocky Rotella (and others) for flat tappet Pontiac engines, due to still having the proper amount of ZDDP (without additives) which is no longer found in sufficient quantities in modern grade API/SM/SN oils, because it's bad for catalytic converters but necessary for vintage flat tappet cam protection. Here's their website to explain it better than I can:
http://www.penngrade1.com/

And searching some older posts around here shows that Vicki Yellowbird recommended Brad Penn also at one time...I know that's another respected name from the past...