Found this when looking for something else - as one does! Beautiful Hinz Organ too!

https://www.youtube.com/watch?v=9HXXEx6pQsM

a few other tracks also on the "toob"

The scores for all Stanley's Op1 and Op4 sonatas are free on IMSLP, originally composed for Flute and continuo. They do have the flute line and a figured bass

http://imslp.org/wiki/8_Solos,_Op.1_%28Stanley,_John%29

http://imslp.org/wiki/6_Solos,_Op.4_%28Stanley,_John%29

Some arrangements on freescores.com for various instruments.