84-86 bumper ends on a 99?

I've seen a few people with the older rear bumper caps on newer XJs... then filling the gap with some diamond plate.. I've got a destroyed end cap and they are just too damn expensive for the 97s and up.. so my Q is how would I go about mounting the older caps and where can I get a custom cut piece of diamond plate to fill the gap?

heres a pic of what I'm talking about..

’97 and newer end caps mount exactly like the old style, basically there are interchangeable. If you want the diamond plate either get a piece and bend it up (easy to do, just 2 straight bends and no compound angles) or buy one like this http://www.c-rok.com/qp.html or this http://xjnation.homestead.com/skidplates.html Personally, I don’t think that they are worth anywhere near the amount of money they are asking for them. You could build them yourself for less than $30 in materials and a little bit of time and effort.

i have an extra set of bumper ends from a 2001. let me know if you want them. they are sitting in my garage.

are you willing to just sell the passenger side?