Yes, I have listened to two sets and they all have the same rumble problem. I believe the rumble is part of the recording because it only existed in the music track, not the blank in between.
I also have the original Mercury LP, which does not have the same rumble problem. However, bass of the original Mercury was significantly rolled off compared to the Speaker Corner reissue. Personally I think the reissue sounded better with the stronger bass foundattion and being closer to what Starker's cello should sound like. Starker recorded the Bach suite on RCA again around 1970 and the cello in the RCA sounds just like the Speaker Corner reissue.