I have had a reply for the keep museum as follows.
The 1st/11th of Foot were indeed on the Isle of Man, though only for a short period of time. They arrived in October 1878 and moved to Salford during March 1879 .
They remained in Salford until February 1881 when they moved to Colchester.

Many thanks for the pointers in the right direction.
Frances can add this information to her manxnotebook page now.