Nothing new or easy.Any current hints or tips to the easiest fix?
Fix strategy: Confirm the key resistance(is it the same on all keys?). Unplug connector at the module and check for key resistance at the plug. No or incorrect resistance fix wire or replace 25 year old tumbler and get new keys with the same resistance. Good resistance check the connector for corrosion or replace module and spend some time determining the replacement module's resistance number for the key.
Bypass strategy: Reprogram PCM. Confirm PCM now works without the 55Hz from the module. Bypass the VATS starter relay. Remove VATS warning bulb.
This is the very short version. The FSM has pages on this.
As most cars are now chipped a insurance investigator will be interested in how a car with a anti theft system could be stolen so easily.(1970s car theft methods will work without VATS)
When I bought my car I got mail order(not ebay) locks for the whole car for about the price of the ignition tumbler. As most locksmiths did not have the ignition key they just charged me for a basic key copy and used the new blank I supplied.