This is how the "brushed" trim turned out on a pair of diy Heresy.   If you have two pair of LSi and one pair are splits, you can start stacking them. Just for fun.

Watched about 1/2 of the video in the link.....  glad to see they found a spot for the Hamburglar, but you couldn't pay me enough to take my children to see that.

Call or email "Master Builders", if you call (my recommendation) ask to speak with someone in the  technical department and explain your situation/condition. They'll provide you with product recommendations. You might have to answer a couple questions beforehand so that they know which department to direct you. Design and Consulting Engineer's and Architect's do this all the time for product recommendations.   The grade or quality of sandstone is probably not that good if it's delaminating, so you'll likely have to perform routine maintenance (annually/bi-annually) to keep it in as a good condition as possible. Let me know if the tech guru's at master builders couldn't help, but I'm 99.9% sure they'll offer you some good recommendations.

I hope you get the Khorns.  I just got mine after 40 years of wanting a set. I'm running an NAD 356BEE which is WAY more power than these need.  I think if I was shopping now I'd be very tempted by the Outlaw RR2160MkII.  It gets glowing reviews, is very well built by a very respected company and is in your price range.

There’s a lot of people out there with unbelievable amounts of money , and they’ll spend it for high quality luxury goods . These are good  looking speakers , very  unique , they blend art with function  ,plus designed and built in the USA ,  worth every penny 🤓

Trim pieces will come off with plastic trim tools or a 2x4 and a mallet. You have to be careful because they are attached with glue and screws. The glue will sometimes take splintered wood with it if you are too forceful. I use a trim tool to get a corner started and either run a razor blade or the trim tool down both sides of the trim piece to loosen before pounding off with a 2x4 and a mallet. 

Bumping 

Good to see you back Matt.

Great set up and project. Love the LSi! You can buff the aluminum trim to look nicer but you will be removing the anodized finish, so the alum will oxidize over time. The corner brackets will not polish up like the rest. Since your set has the fiberglass in the finish, you should not use duratex. A good cleaning could work but a light painting with whatever level of sheen you prefer is best.  

My center channel (with Denon) is 100% in your face on radio announcers and TV News broadcast panels with so little going to the Khorns. You don't have to be sitting in a position 10.0000+_ .0002" of an inch. The voices are in the center no matter where you stand. JJK