Blue Hand Built Vase - Alex Blair, Stornoway Pottery?

I recently acquired a hand built column vase (20x8x8 cm). I believe, from the mark on the base (similar to that in “British Studio Pottery Marks” by Yates-Owen & Fournier), it is the work of Christopher Bayley who worked at the Aldermaston pottery (1975-77). I notice from the ‘Aldermaston’ thread here on the forum (https://www.20thcenturyforum.com/t3346p15-aldermaston-pottery?highlight=aldermaston) Christopher Bayley had a Yorkshire studio after leaving Aldermaston.

I have been unable to find anything about Christopher Bayley or his studio on the internet so I wondered if anyone knows if this is his work and whether he used this mark after leaving Aldermaston?

The vase has a pin prick in the glaze above the pedestal on each of the four sides and a faint ‘A’ scratched into the base also. Is it likely this is a test piece? I'd welcome any thoughts or comments.