That one was leased from Timeless, and may still be available as such. I think Blakey did several sessions for Timeless, not all of which had U.S. release. Seems as if I remember one that was a bigband, or near bigband, date, recorded live(?).
And didn't the later (last?) Messengers do a thing or two for Black Saint/Soul Note?
You are right. It was on Timeless. I believe one of the last Jazz Messnegers left some recordings on Sould Note. I don't own them, but they should be pretty good.