NEED INFO ON 15x8" MAGNUM WHEELS

I got these set of Magnum 500 15x8" from Mustangs Unlimited and need to install a set of beauty rings on them ( I know they don't come with them) they have rusted quite a bit in the outside edge and also on the joint of the center piece and outer rim. I tried some corvette trim rings but they don't go in all the way and about 1/2" sticks out. Has anyone tried to fit a set of trim rings in these wheels and obtained a good fitting? I will like to know who sells them or where to get them. Thanks.

Thanks, for the response. They are almost out of chrome from the lip to the center of the rim. I did clean them and at one time did chrome touch up job with caswell plating brush chrome kit. Now they are very rusted at the lip area and the only solution I see it's to use trim rings to cover them. My chrome shop does no have setups for wheels so chroming with them results in yellowish areas and besides this coming July the will be eliminating chrome plating due to EPA new restrictions. Maybe I could find some one that have tested trim rings in these wheels and got a good fit.