Pony Kegs? Wow! I haven't heard that term in a long time. I'm not sure of the exact definition of the phrase, but when I was a kid, a pony keg was a little shop that usually sold snacks, wine and beer, and maybe a few other things. From the ones I remember, you pulled up to a loading dock sort of configuration. The guy took your order and brought whatever you wanted to the car. I think a beer drive-thru might be the modern day equivalent to a pony keg.
Mike's Pony Keg on Montgomery Rd. in Silverton is still in business. When I pass by, it reminds me of the places I remember when I was a child. From the online listings, I see there are a few other pony kegs still in business.