Peter,
Dissenter Baptisms 1817-1849 are on Brian Lawson's site. The only one I can find on the actual record book is Sarah 1826 . It is not like the other R.C. Records as it does not record godparents, only date, parents and child. I will keep an eye out for any other records which may help you. Canon Alger is a very busy person, the clergy from St Mary's are responsible for three parishes.
Marie Radcliffe