Correct me if I'm wrong here Myrany, I don't own a REO unfortunately, but just about any 510 topper (carto,dripper, etc.) with a hole through the bottom 510 positive post could be used on a bottom feeder; I think. It just uses the bottom air feed holes to funnel juice from the lower tank (squak bottle) up to the coils or filler material. Adversely to carrying a separate bottle to drip from on high, right?

And, the bonus is that ANY 510 topper will work on a REO, but you just do not get the convenience of squaking from the on board lower tank if the topper does not support it. More options, always a plus in my book! So, since the the 357 has a hole through the positive post, it would be a perfect no fuss way to enjoy a dripper without rebuilding. Right? By the way, I envy your REO's and will buy one one of these days; right after a Provari! Bruhahahahahahahah!