Grok was responsible for at least one record: a single by Day Costello, with 'Free (Unlimited Horizons)' on the 'A' side and '(To Be... To Have... To Do...) Go Clear' on the 'B'. It came out in 1970, and had a catalogue number of GRS-1; there doesn't appear to have been a GRS-2. 'Free' featured as the 'B' side of Costello's 'Long And Winding Road' single for Spark, that same year (SRL-1042, 7/70), so it seems reasonable to guess that this single pre-dated that one and that Spark used one side of it as a quick, cheap 'filler'. The labels were mid-blue with silver print, and they had the label name in capitals in a box at the top; the style of the matrix number in the run-off suggests a British Homophone pressing. Costello had previously recorded a couple of singles for HMV in 1964-66 and one for Decca in 1967 under his actual name, Ross McManus, but as none of his records sold well his voice is probably best know to the public through the R. White's 'Secret Lemonade Drinker' television advert from the 1970s. His son Declan was to enjoy a much greater volume of sales under the name Elvis Costello. Thanks to Robert Lyons For The Info.