Thanks for the details, I see much clearer now ... as far as it goes, that is, because the MCA policy of re-cataloguing (or rather re-appropriating) former records has produced a mess, as becomes apparent from what you describe. And as far as Peacock is concerned, the messing up already started with the ABC Dunhill take-over ... thx again for the clarifications!
OK, front cover of my copy is from about 1979/80, as it has the MCA Records logo in the top left-hand corner of the front cover, with the original Peacock number PLP-139 underneath it. Back cover has MCA logo and address, and Peacock number. However, front also has new number MCA-28022 in the top right-hand corner. Labels are MCA blue sky clouds and rainbow design with MCA-28022 as the catalogue number.
This series of MCA-28000 gospel reissues dates from about 1981, simultaneous with the Jazz Heritage series (MCA-1300), MCA Impulse (MCA-29000), Past Performance series (MCA-27000), Platinum Plus series (MCA-37000), some new pop compilations (MCA-1500), and some others.
The MCA reissues of ABC-group labels (as well as their own) exist in different combinations of original labels and covers, or MCA labels (either brown-and-beige or blue sky/clouds/rainbow) and covers, so you can have original pressings and covers with new numbers, new pressings in old covers, old pressings in new covers, and so on. (Some of the 1979/80 pressings from just after MCA's purchase of ABC are on MCA's brown and beige label, but with the original catalogue numbers). Some of these sold well enough to be repressed and re-printed so that they were all on MCA with only the new number showing on all parts of the covers and labels.
MCA's intent with the ABC catalogue was to make MCA the primary label, and their new number the primary number, but as they had so many pressings and covers left over, stamping the new number on them was probably the most cost-effective way of achieving that in the short term, but it doesn't match this site's "as-on-label' ethos. I seem to remember an article in either BILLBOARD or CASHBOX about this at the time, but I'm damned if I can find it online. Anyway, it looks like I need to create a separate entry for my copy - if only there were a "copy entry" function here!
I've got an MCA issue of this, but I'm not sure at the moment whether it's an ABC/Peacock pressing with the MCA number stamped on the front, or an actual MCA re-pressing after the old ABC stock ran out. I'll check at home tonight.
The 1973 release is most probably a re-issue; the original Peacock LP #139 was released in 1966 or early 1967. I have seen covers of this LP bearing the "MCA Records" logo in the upper left corner, so there was another re-issue in 1979 or 1980. Impossible to say without sleeve and label scans.