There is a photo in the MNH library clearly showing the heightening of the gable and possibly the rear stair-tower went on at this time. The rows of very narrow upright windows on the front are like the front of the Clucas-Murrey-Teare House in Chapel Row, Douglas, see write-up in Proc NHAS Vol XII No 1 p 75. Front can hardly be later than 1700, allegedly incorporates earlier walls.
I understand the Chapel belongs to "the nation" but am unsure of access arrangements - apply MNH I suppose.

Seemingly the Friary cannot be a house of "Architectural & Historic Importance" unless the IOM Government has defaulted on its international convention obligations?? which are to protect such.