Ah, now I know what seal you were asking about on another post you made. They are unavailable from Honda now but you might be able to score one on eBay. You may have to surf the Web looking for rubber edge seals, there are many different cross section seals you can find and one or another should work as a decent substitute even if the originals can't be found. The link below has several different styles and some searching on the Web should turn up many more sources.
I am looking for the same seals for my 83 interstate. I just bought it. I rode it once last year when I was buying it and haven't rode it since. I am going to do a little work on it before I get it on the road.
I need all three, the trunk and both saddle bags. If you have any luck finding them please post here. I will do the same.