I just came across this ad for Nic Jones's first album on CD on Amazon UK.
Although a line in the ad suggests that the available stock (8 CDs) is located in Japan, the seller is listed as music_by_mail_uk, who turn out to be "INSIDEOUT SUPPLIES LTD" at a Harrogate address identical to that of several of Dave Bulmer's former trading operations.
The first reviewer in the Amazon listing warns off potential purchasers, citing some of the history of Celtic Music, but others appear to have been happy with their purchases.
Your Wikipedia listing (which works fine for me) is a valuable contribution to discography, and shows that, whatever else he failed to do, Dave Bulmer did not just spend his time sitting on his assets, but managed to produce a valuable body of work, from CD re-issues of classic albums like Archie Fisher's first LP, to original recordings such as Phil & June Colclough's "Players from a Drama" (which I recommend very highly). His reproductions of O'Neill's tune books were heartily welcomed when they appeared, making these legendary collections readily available.
I also thought he was responsible for "Clan Alba", a double album from Dick Gaughan's supergroup, but that is listed in Discogs as CLANCD001, from Clan Alba Productions.
Good luck with the project. Hope you manage to fill the gaps.