id guess you could try something off just about any 53 model gm they'll probibly all need a little modifing but you could probibly make it work. ive got a 52 buick and my friend has a 52 chevy it looks like you could probibly make the trunk lid work with some mods, but it would probibly be just as easy to fab something if you have access to an english wheel or just feel like pounding alot.
Is it a 40, 50 or 70 series? The tag will say next to body type. A 40 is a Special, 50 is a Super, and 70 is Roadmaster. The Special is 53 Special only. the others will fit 52-3 50& 70's, 52-3 Cad 62 sdn,75, or 50 Buick 41, 41D, 4dr, all 50-70 series exc sedanette. 51 buick 50-70 series exc 56S sedanet, 59 79R Cad 50-51 62 sdn, 61 & 75. The earlier ones don't have as high of a hump as the 53 ones. This is according to Hollander's.. they sometimes will leave something out if it takes any type of fab to make it fit, even though it does. So your results may vary.
A guy I know used a 52 caddy trunk lid on his 52 buick special...bolted right on and had a nicer profile......sorry I don't have an interchange book to see about a 53!
Does anyone think this trunk will fit the 1953 buick riviera. http://cgi.ebay.com/ebaymotors/1952...TruckQ5fPartsQ5fAccessoriesQQsalenotsupported
I have a very decent '52 Buick Super trunklid on a car I'm parting out, could set you up with it reasonable if it will work for you. Parting a whole car and I have other stuff too if you need anything.