Very Eavy Very Umble by Uriah Heep mispressed record, read on!

So I recently purchased a copy of this, a pristine German pressing.

But while perusing my collection I found I did indeed already have a copy although it was  a late 70,s reissue on the Mercury label ML8004. It also became obvious I have never played this record...….

Thinking this was a great opportunity to test the sq between this and my mint German pressing I went to cue the Mercury issue up. However it looked odd.
Side 1 has correct Heep label showing the correct 4 tracks and ML8004 cat number but looking at the vinyl I could see only two long tracks?
So dropping the needle on side 1 and..... Absolutely definitely NOT Uriah Heep!
No idea who/what but some trumpet fixated jazz/swing music!
Trying the side at various points revealed it was this on side 1 all the way through and no Heep to be found anywhere!
Now side 2 is indeed the full and correct Uriah Heep side 2 with correct side 2 label.

So it appears I have a mispressing but I can find zero information about this on any internet search I have tried so far.

My questions are;

Has any member here heard of THIS particular mispressing?
Or does any member have a good source of information for mispressed records, like a specialist dealer etc.

Fortunately the German pressing is correct Heep both sides!