Out my way there's hundreds of old cottages like this. It looks like theres a hell of a lot of salt coming out the brick. I've been advised by structural engineers, the bricklayers guild, damp and salt specialists (each with their own ideas) to first use a minimum 12mm render 3:1 minimum with waterproofer and a salt inhibitor (12mm thick to give the additive a better chance to fight against the salt). Then Dab either a foam back board or foil back board depending on how bad the problem is. I've only ever used foam back boards where the outside brickwork has been painted or terelened straight onto the bricks preventing them from breathing and forcing the damp into the house. In fact i've only done it twice, most people have listened to the suggestion of having their houses shot blasted and everything works out great. Anyway, the boards are stuck then we drill 2 holes throught the board into the brick and fix the board again with hilti anchors (Hilti Online - IZ Insulation anchor). Skim up and jobs a good'en.