Have a look at the " Directed Electronics " web site, they make remote car starters and key chip foolers. The tech section might give you some hints as to operation.

From you description, it sounds like the key is an actual pin and tumbler type Vs the electronic ignition switch used on later cars. If so, it should have a DAS X system ( not to be confused with the DAS Xentry diagnostic tester )

I've run DAS X with a key stuck the the antenna when testing a ECM and DAS box and had no problems.