I sometimes work with a small regional sound company, which runs an old school analog system based on Meyer MSL-3's and 650-P's, Gamble consoles, and Crest Pro series amps. We have a few digital consoles, but everything else is analog.
We do a mix of events, ranging from city park gigs with 2 pairs of MSL-3's, to festivals with a full rig. As such, the amp racks are set up as low density modules, which can be combined as needed.
Each rack is a custom box, grey carpeted, in our standard 24"x30" footprint, containing a 10u shock-mounted rack section, with a shallow cable trunk section above that for looms, AC jumpers, etc.
Covers are slip-in panels with butterfly latches, which we store in the top section when not in use. The older (main) racks are built with a standard trunk lid with a 2" rise, the newer monitor racks are built with a flat lid, with flip over hinges.
Each of the main racks are loaded with a pair of Meyer processors, a pair of Crest amps (7001 and 8001), and a 2u drawer for adapters.
I/O and power is on the rear.
For power, we use a L14-30P on the supply side, powering a single amp per leg, and also split out to a pair of L5-30R's to power subs/etc.
Inputs are XLR, outputs are EP4.