I've been doing a ton of searching and have not yet found a "reinforced" hinge plate just stock hinge plates. I contacted airsoftbuddy about the hinge plate and they informed me they were passing the comment onto TSC. I just hope TSC does make a hinge plate. Other then that you could try what this individual did with a PVC block.
http://gasguns.info/forum/viewtopic....t=3318&start=0