Used to have COD4 GOTY and used the code for the free maps. God rid but have now got hold of a vanilla COD4. Will the maps I downloaded when I had the GOTY edition still work with a normal copy of COD4?
AFAIK yes - assuming whoever you sold the GOTY to hasn't used up the all the downloads. If you go into your transaction history you should be able to re-download and re-install the map pack.