(The key is: don't try to make sense of BattleTech's strategic considerations. The setting doesn't work if you look at it too closely. If the Successor States had an ounce of common sense between them they would all have either moved their manufacturing facilities or built new ones as far away from their borders as possible. But it seems every other raid or border skirmish is over a "'mech manufacturing plant" one or two jumps from the border.)
Defiance Hesperus is a great example. It's very central in the Inner Sphere, so it's threatened by a couple of other states that could attempt to blitz deep into the Lyran Commonwealth to cut off Hesperus and annex it. And if that's not bad enough, the Skye seperatists are just around the corner and have tried a couple dozen times to grab Hesperus, cause it's such a juicy target.
The only possible explanation to not just tuck away something like that in the deepest confines of the LC core land would be that the necessary infrastructure for such a large production facility is so vast and so dependent on everything lightyears around it, that it can't be recreated anywhere else, even with a shitton of resources and time.
Still a rather flimsy excuse, but at least some excuse. After all, this gives us the pretense we need to dust off our trusty stompy robots to kick butt and take names.
BattleTech is about as niche these days as it's ever been. Back in the 00s it was relatively easy to find BT minis (I found a lot of cheap pewter knockoffs) off the back of the push Wizkids made with MechClix. There's a reason I got used to playing with 4th ed. box set-style cutouts on stands. Still, as @RomanesEuntDomus (I think?) showed, you can get some pretty good shit online
About a year and a half ago, I stumbled over my old mech miniatures (yeah, all 4 of them) and I was reminded of the good times when I played BT with a bro back in school and how I, being a poorfag, was never able to buy more of the mechs that I love, like the Atlas, Devastator and so on...
So I checked online, thinking that I might find a handful of miniatures in some obscure part of the internet, that might still have a small collection of very old mechs around. I simply didn't expect to have much variety to choose from. And lo and behold, a shop that had virtually every mech I ever wanted... and then some.
Now I have a collection of like 40 mechs... and like 20 CVs.
You can order them from IWM directly, I order mine from a German shop called
Fantasywelt, they even got an English page, maybe they deliver to your neck of the woods, too?
But apparently, there's a major issue with shipping from china for many suppliers due to the Chink Stink, that's why many miniature shops ran dry.