So far so good and the lump has been identified as an enlarged salivary gland with no indications of malignancy. Why I don't know yet, but speaking to the vet tomorrow to see about it. Lump is bothering Wilf though (its above his jaw just under the ear) and antibiotics didn't help.
Fingers and toes still crossed for my trek to Cambridge and back for Wilf's work-up and hope that the cancer hasn't spread. I've got to get up at stupid o'clock to catch the 04.25 train.