From WWII through the 50's and 60's (maybe longer) US military uniforms were a blend of wool and mohair. GP is probably referring to the returning soldiers from Viet Nam. Ironically cautioning them to beware of LA sucking them in when they think they are safe at home. "Three years of pay" would be the wages earned on the tour of duty. The song seems to me a swirling mix of ominous apocalyptic warning to the yet innocent from the fundamentalist country boy simultaneously shocked and entranced with the city of sin. DS