Last B&M Steam thru Hamilton & Wenham

Does anyone have a date / details of the last revenue / regular use of steam power on the Eastern Route thru Hamilton & Wenham? I'm aware that steam was still used on the Gloucester Branch for some time after all the Portsmouth trains went to diesels and RDCs.

I don't know an exact date. Last steam to Amesbury, MA was 7/1/1950, but that was presumably when a 44-tonner was assigned as the switcher. The place to look would probably be a library archive of the Portsmouth Herald or Foster's Daily Democrat - when the Portsmouth (NH) engine house stopped servicing steam, I expect at least a few employees were displaced and several structures were expected to be removed from the city's tax rolls, so it was likely to make the news.