Definitely not just a row of discrete LED's. It's a multiplexed, monolithic LED display with "bubble" magnifiers. Like zevon8 says, it looks like a calculator display - old school. Similar to HP-5082-7200/7400 series displays. The digits will probably be about 0.2 inch tall when viewed. For a dollar each, I'd probably buy a couple just to play around with 'em. If you're a PIC (or AVR) man, I'm sure it wouldn't be too tough to program one to use as a driver. Discrete IC circuitry, however, will be quite messy.
And, I remember Poly-paks, too (from the back of Popular Electronics).
JB