Sling Swivel cap for 870 20 gauge

[brimmyfish]

I have an older 870 express magnum 20 gauge that I would like to buy a magazine cap for with a sling swivel stud. Looking online they offer more than one model, and I have heard that some may not fit the older style guns. After looking over a serialization chart it looks like my gun was made in 1992. And it appears that remington doesnt make the Express Magnum 20 gauge anymore, but instead just the Express 20 gauge. So what should I look for to make sure that I get one that will fit?

Thanks

[ClayW]

I've bought 2 and both haven't fit.

Did you find one that worked?