Ted;
You say it wasn't dovetailed lumped, are you positive of this? I interpret it, that is speaking of the original joining of the breeches, which is not to be confused with dovetail chopper lumps. I would not be at all surprised if it did not indeed have dovetail lumps. This has nothing to do with the sleeving, which I presume is the conventional method of cutting off & boring out the breeches & sleeving in new tubes. "Nota Bene" they are not "Mono-Blocked".
I know neither you nor the ad said they were, but so many do.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra