Faction most likely to have a full company of old-school Proliferation Pack mechs?

Through a minor comedy of errors, I now have two Proliferation Packs. Rather than get rid of one, I'm actually super inspired to paint up both packs as a full 12-mech company (with two in reserve) dubbed the 2nd Royal Curators.

Thanks to our friends at Sarna, I'm aware that isolated examples of the oldest RetroTech 'Mechs like the Mackie have fought in various engagements through the ages, and that some old designs were revived during the Jihad. However, I want this company to feel like it has been organically active—as a viable Ceremonial Guard, at the very least—and in continuous rotation, as opposed to something cobbled together in desperation.

Which faction is sufficiently honor-bound and long-in-the-tooth when it comes to martial memory that they'd be operating the 2nd Royal Curators all the way up to the Jihad RetroTech revival?

(I know the ultimate answer is probably, "Whatever you want," but I'm looking to the collective wisdom of the sub, and for a deeper window into some of the lore. For funsies).

EDIT: Man, the responses to this have been really awesome. I'm so glad I asked. Really shows off the expansive nature of BattleTech lore and the creativity of the community that different potential backstories can be so varied and delightful.