Pitlamp's reference is to one of the 2nd. series of DCA Newsletters - these were actually printed, as opposed to duplicated. (Series 1 was duplicated, edited by Geoff Workman and went Vol. 1, No.1 - up to Vol. 1, no. 12.) Unfortunately the issue numbering of the 2nd. series was perhaps not all it should have been so this is actually issue number 5, Sept. 66. of the 2nd. series, which started again with volume 1. Nos. 1 to 5 were printed professionally and the editor was John Garrett but after editing 5 issues he gave up and the next issue, edited by P.Taylor, was duplicated and was undated (though produced in Dec. 1966) but was called No. 6.
The Paul Deakin 2-page article refers to the start of the digging on 3rd. April and then says: "The dig, which was a hundred feet long, was completed on the 22nd. May and the party (Deakin, Watt, More, Parkin and Bridger) passed through Oxlow to Giants." He also lists the cavers involved in the over 600 man-hours of work required to make the breakthrough. The Editor then adds a comment about possible difficulties with the farmers at Giants and Oxlow and says that any party wishing to make a through trip must gain permission from both farmers.