There are some useful articles on the 'family tree' of Scottish paperweight makers that set out who worked with whom, and when, and what companies they set up, how long they lasted, and so on. Dave Webber wrote two in the PCA Bulletin (2000 and 2003).
Peter Holmes and Willie Manson left Caithness to set up their own companies, and Peter Holmes subsequently left Selkirk and set up Scottish Borders Art Glass. Similarly John Deacons left Perthshire to set up his own company, which he still runs. Caithness went into administration in 2006, taking Selkirk down with it, and was taken over by Dartington Glass, and now operates as a much smaller company.
Whether early Caithness paperweights are valuable depends very much which design they are (and don't believe the Charlton catalogue prices - most are wildly optimistic). There are no 'early 1960s' Caithness paperweights, incidentally - the first ones were issued in 1969.