Ray, I just happened to come across this reference in Manx Notebook to S B Moffatt, schoolmaster and the name rang a bell. Have you seen this ?

£30 a Year for Schoolmaster.
In 1843, there were 114 girls in the day school and 101 in the infant department. The numbers in Thomas Street Sunday-school were: Boys, 120; girls, 193; total, 313.

The day schools were maintained by contributions from the Chapel-folk and as many parents set small store on the value of education, the committee had neat difficulty to obtain the school fees. Many of the children's parents were too poor to pay and others ignored their indebtedness to the school authorities. The master of the school was S. B. Moffatt. No school teacher of the present day would envy his position or covet his salary. In 1844, he writes an appealing letter to the committee for an increase of salary, after 32 years' service in the school. The letter concludes: "I hope you will take the matter into consideration and i am persuaded that every reasonable individual will consider £30 or £33 a year a very inadeqeuate remuneration for discharging the arduous duties connected with such a responsible situation."

A letter written several months later, states: "It would be more pleasant for me to labour if I had the fixed stipend of £.40. I can only add that you will not consider me too troublesome in making this request; at the same time, if possible, I should like a little more encouragement."

www.isle-of-man.com/manxnotebook/fulltext/ts1935/text.htm

Might this be the father of the Samuel Benjamin Moffatt you're trying to trace ?

Jean C