Quick Aside About Bug 'Mechs
TR:3025 estimates the Successor States use 5000 or more Stingers. The 51:42:32 ratio suggests the actual numbers would be around 5100 Stingers, 4200 Wasps and 3200 Locusts; about 12500 altogether. That works for a BattleDroids-ish setting with no other light 'Mechs and 39500-41500 'Mechs overall; but it gets a little tight once we move into the 3025 Housebook setting, even with 55000 'Mechs overall.
51:42:32 is also very close to 25% (9/36ths) Locusts, 33% (12/36ths) Wasps & the rest (15/36ths) Stingers. TR:3025 says the -1V accounts for "more than 75 percent" of extant Locusts, and I can't help but notice that 7/9ths is the simplest fraction to fall between 75% and 80%; you could almost fit all this on a 2d6 table. If the two other bug 'Mechs are similar, then I might expect the -1A to be 9/12ths of all Wasps and the -3R to be 12/15ths of all Stingers.
HM:FWL's manufacturing chart shows 187 medium 'Mechs/yr, while MW1e's Encounters and Lance tables would result in 191/yr. It's impossible to make the tables yield both 141 lights/yr and 187 mediums/yr (well, technically you can, but you'd have to use negative values for the frequency of light and medium lances), so apparently I have to increase production of some medium 'Mech by 4/yr.
The Phoenix Hawk, Hunchback and Hermes II seem like good choices because they "increasingly dominated" the League's regular regiments; but the Hermes II, Wolverine and Griffin are bad choices because they'd disrupt the list of most commonly produced 'Mechs. The 486 'Mechs shown on the chart have an average mass of 49.002 tons--I'll try to choose a 'Mech which keeps the chart's average mass as close to that as possible.
"Except for the period between 2953-68, when it controlled the Liao Atlas and Victor production facility on Carver V," HM:FWL says "the only new assault 'Mechs produced by the Free Worlds League during the past century have been Awesomes, BattleMasters, and Goliaths," and that there's "four active production lines of this type, producing an estimated 30 units per year"--yet the production chart shows 34 assault 'Mechs/yr, including 11 Stalkers.
The obvious solution is to replace the Stalker line with another one producing 7 Awesomes, BattleMasters or Goliaths. I'd go with the BattleMaster, making it about 2/3rds of the FWL's assault production, since the common BT3e 'Mechs make up 2/3rds of the FWL's production overall. (Though I have to say it's also tempting to replace both the Stalker and the BattleMaster with, respectively, the slow and fast variants of Longbow.)
Earthwerks et al
HM:FWL says the FWL produces about 500 'Mechs/yr of 24 types at 17 facilities, yet the production chart shows only 486/yr at 13 facilities, and replacing the Stalker takes us from 24 types down to 23.
The Earthwerks corporate profile in that book mentions a Thunderbolt line which would fill that gap nicely: it takes the number of 'Mech types back up to 24; being a heavy 'Mech, it doesn't screw up the light, medium or assault counts; and 14/yr is pretty close to what heavy production lines on the chart average (about 12.5/yr). (There's a small chance that I should reduce the Thunderbolts a little to increase Quickdraw production by one or two per year; it's something I'll have to watch for.)
Curiously, the corporate profiles don't mention the Awesome line on Irian, the Stalker (or any other assault) line on Shiro III (they mention Quickdraws instead), the BattleMaster line on Keystone, nor the Shadow Hawk line on Calloway VI. If these production lines got absorbed from other locations, that would help bring the number of facilities up to 17 as mentioned in the text. No doubt some of the shuffling can be chalked up to the reconstruction following Anton's revolt.
[Edit, 2017 March 31: I've removed the summary chart because a couple of the changes are "squishy" and I'll have to treat them as such moving forward; also because charting the manufacturing by location is only really useful for identifying the FWL's seven inactive production lines, which involves analysis I haven't done yet. /Edit]