How old? Lionel has done HO at least 3 times. The 50's era stuff is going ot be tough. The 70's stuff was a mishmash of different manufacturers. There shopuld be nothing special about them, motor with two wires going to the track pickups.
Here's the HOSEEKER page for what thye have of Lionel HO
http://hoseeker.net/lionelhoinformation.html
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.