It’s hard to tell for sure until the rim lava has been removed, but, with the exception of area of compression on the rim of the lesser used pipe, the rims look like they could be in decent condition.
I’ve removed worse with spit and a rag. The enzymes in one’s spit dissolves the buildup. Some people prefer cold coffee and a rag to do the same thing.
You can use a piece doweling with a rounded bottom, wrapped with glass paper to carefully grind away the cake on the chamber walls. Then it’s shank brushes and bristle pipe cleaners to clear the airway.
If you want a professional job, contact George Dibos, georged on this forum. The man is a wizard at restoration and the only person I let touch my pipes, though rustypiles on this forum is also a wizard. I just don’t know if he’s doing restoration these days.
If the rims need to be topped, staining them to seamlessly match is tricky, but George is a master at it.
The pipes are good sized. “As is” the set would fetch between $700 and $800. Cleaned up, with clean rims and a sound chamber, you’re looking at $1100, tops. The bite damage to the button limits the upside.
This also supposes that the briar hasn’t experienced any structural decay from long term exposure to heat.