Your Citation 12 was very likely built from a kit (I built a couple of them). New (circa 1971), it retailed for $295. Garnered great reviews at the time. It has dual-mono construction and is amazingly dynamic for 60 watts/channel. Works best with its matching preamp, the Citation 11. Should have no problem driving Advents, as I used it to drive AR3a's for years.
-Ed
-Ed