To return to the original question ...
After a little investigation and a bit of speculation, I reckon there were at least three mid-70s attempts to present broadly the same selection of Glen Brown instrumentals, none of which progressed beyond test pressings.
There is a ten-track album with the matrix GROL 510 (currently available!
http://www.ebay.co.uk/itm/76-GROUNATION ... 25a6e8a081, helpful samples in the player), an eleven-track LP with the matrix MIC TMC 2662 (
http://djgreedyg.proboards.com/thread/1 ... k-blank-lp and
http://www.rootsvinylguide.com/ebay_ite ... ase-reggae) and one with the matrix GLB LP 001, which looks like it had twelve tracks (
http://www.rootsvinylguide.com/ebay_ite ... ggae-grail).
It seems likely that GROL 510 was pencilled in for release on Grounation as Glen Brown Meets Tommy McCook At Crossroads Caledonia Place and is the album which became known as Horny Dub. MIC TMC 2662 could well have been the so-called Micron blank which sometimes appeared in a plain cover stamped Tommy McCook [In] Dub. GLB LP 001 might just have been the one intended to be "the LP Comming The Sannic Sounds", as advertised on the Pantomine 7" Determination Skank (
http://www.rootsvinylguide.com/ebay_ite ... antomine-7).
Despite the liner notes (
https://www.kudosrecords.co.uk/release/ ... ccook.html), I don't think the Dub Store reissue, Sannic Sounds DSR-CD-004 (
http://www.reggaerecord.com/en/catalog/ ... yword=3425), is Horny Dub. For one thing, there's an extra track. I think there are probably nine tracks in common. The last track on Horny Dub, a Mr Ball Head Akekin cut, is replaced with Flute Instrumental (on the Jump Back Baby/Really Got A Hold On Me rhythm) and Brand New Man (a banging version of Brand New Me).
I can't help wondering whether the Dub Store reissue is actually MIC TMC 2662 on a number-of-tracks basis and because I find it so tempting to imagine that GLB LP 001 actually is The Sannic Sounds. Someone has carefully inscribed those words on the label - which is a different blank label to GROL 510 or MIC TMC 2662. GLB LP 001 has a large central indentation about 2.75" in diameter compared to Horny Dub's modest 1.5" and different in appearance to MIC TMC 2662.
The eBay listing for GLB LP 001 suggests that there were six tracks on each side. Allowing for crossings-out, Side A looks pretty much like the first six tracks of both GROL 510 and DSR-CD-004 but the listing for Side B suggests some differences: When Something Is Wrong With My Baby and Dirty Harry are right in the ballpark and From The Pip and (Illegible handwriting .. ??) are hard to pin down but Merry sounds like another version of Merry Up, which, together with a version of Va Va Voom, would be unique to this album.
I could be wrong though.