The bits of info that I have picked up thus far via trad gang and another forum indicate that one Randy Dehnel, who later started Saxton Archery, was probably the bowyer who made the Nirk longbows.
However, there is a conflicting opinion that Martin / Howatt was responsible for manufacturing the Nirk bows.
So, it's hard to know what to believe.
Are / were Saxton bows a quality product? I know Martin / Howatt are indeed well received and respected.