Yep, those are the ones. Nice mod.

We never tried it with Tamiya, I'll dig them out and give it a shot some time. I bought a bunch of them for Xmas one year, but we didn't use them too much for lack of battle space. I have the indoor space to mess around with a MSR, but with 3 coaxs battling, things get small quick. By the time the winds died down enough in the spring, any RC spare time went to planes or tanks. I think a few are still unopened and I have a pile of spare parts as part of their promo.