A little about the ship GLEN ROY
GLEN ROYwas a schooner or brigantine built in 1839 at Hillsborough River, Prince Edward Island, Canada. She was originally registered at Charlottestown, Her registry was transferred to Liverpool in 1841 owned by T.McKay
From 1860 until about 1870, when was sold to Whitehaven owners she was a brigantine, in these years owned by
T.Thomas of Cardigan and operating in the Mediterranean trade. Lloyd's Register 1867/68 lists voyage Cardiff/Mediterranean with coal .
GLEN ROY was reported to have sailed from Whitehaven bound for Dublin with coal on the 24th February 1873 and was assumed to have foundered in a severe storm on Tuesday, 25th February1873.
None of the above concerns your question but important detail.
The easiest way to find his certificate detail is to contact NMM Greenwich using this form.
http://www.rmg.co.uk/researchers/library/masters-certificates-request-formIf its no go there, post again and we will see what can be done at Kew (btw The correct piece numbers are BT124/9 and BT124/10) but in all honesty your best bet is Lloyd's Captains Register at London Metropolitan Archives. I would have thought the cost they quoted for a search was reasonable. However my guess is he only captained one vessel but theres only one way to find out.
Also search Lloyd's Lists. These will tell you where GLEN ROY voyaged to and maybe some personal detail on her captain and owner. I think Australian Maritime Museum have copies.
On Crew Agreement has survived in Kew piece BT99/152
http://www.nationalarchives.gov.uk/catalogue/displaycataloguedetails.asp?CATID=3174103&CATLN=6&Highlight=%2C13288&accessmethod=0