<strike>Here's how I got GMG guard rep without shooting anything:
Make new character, /restart Corsair. Sell ID for Recruit or Civilian ID.
Fly to Atka Station in Sigma-17, take Samura bribe from bartender
Fly to Lux Liner Hawaii in Sigma-19, take Kishiro bribe from bartender
Fly to Gas Miner Naha in Sigma-13, Quad bribe the GMG using 2 Samura NPCs, 1 Zoner, and 1 Bartender.*
Fly to Sakhalin Station in Sigma-59, use /droprep to get GMG Guard IFF, and buy the ID. (I had to drop Kishiro and GMG)
*Procedure to get quad bribe: First refresh the bartender by using F1 until he offers a GMG bribe (and type a message in /l to prevent being kicked for base idle). Then refresh the bar by visiting another room until you can get all NPCs to offer GMG bribe. There are three GMG NPC's, two Samura NPC's and one Zoner NPC on Gas Miner Naha. The GMG NPCs won't talk to you because your rep will be below hostile, but that's okay because the other NPCs offer GMG bribes. Your odds of getting 2 Samura and 1 Zoner NPC are (3/6)(2/5)(1/4) or 1/20. To increase odds of getting a GMG bribe, talk to the Samura/Zoner NPCs to get rumors out of the way. You may take a Republican Bribe and ALG bribe from the Samura NPCs and a Zoner and Outcast bribe from the Zoner NPC. I was able to get the quad bribe in no more than 20 minutes.
Of course, your rep will be really wacky from having used /restart Corsair, so many bribes will be necessary to have a proper GMG repsheet.</strike>