I haven't talked publicly about this match, but spoke to TM a long time ago and he was considering the same helmet as you are suggesting, as the RS helmet. It's worth noting that the same helmet is also missing the neck rubber trim, just like the RS helmet is missing it. I've also forwarded those thoughts to Simon of RS about a year ago. I consider it a likely candidate, but so far, it's still too hard to make a 100% positive match, but it is the best candidate to my knowledge.