How would I replace lost keys for a 1987 Cadillac Brougham?

I can't find the keys to my 1987 Cadillac Brougham and I've looked everywhere. Does anyone know how I could get them replaced?How would I replace lost keys for a 1987 Cadillac Brougham?No GM codes past 15 years reliably. Automotive locksmith is a good alternative. Another problem is you may not have a GM dealer, since they filed bankruptcy on 6/1.How would I replace lost keys for a 1987 Cadillac Brougham?You should contact authorised dealer with proof of ownership and VIN number.