Help ID’ing a M4 GBBR Magazine

[Ronin0033]

Hive mind, I’m struggling to get a precise ID on these mags I have. They came with a G&P M4 (WA based) GBBR, so can presume they are for that, but have no idea who made them. 
 

PMag shells fit nicely, but have been filed down at the front slightly. 
The inner gas tanks are totally bare, but don’t seem to match any others I’ve seen. 
 

Help me hive mind Kenobi, you’re my only hope… 

[Chev Chelios]

Gen 1  GHK mags or original  WA ones that came with the WOC. 

[Ronin0033]

Thank you, pretty sure they aren’t gen1 GHK as I have one and there are a few differences, but maybe original WA/WOC though.  

[hitmanNo2]

They're definitely not OG WA. They could be Iron Airsoft. They're the only WA spec mags that came with a polymer Pmag shell iirc.