Mintons plate, Masonic, Heraldic symbol or....?

Minton's Willow Pattern dinner plate with a cross keys symbol to top that I haven't seen before. Can't make out date code but prob late Victorian from backstamp. Any ideas welcomed

 

Crossed keys are Roman Catholic - Papal. Keys of St Peter and all that. Now, on the back, you've Pet.Coli . So, I'd surmise that Pet here is an abbreviation for Peter. I think Coli may be short for College or Collegium. In other words, your plate was made for a St Peters College somewhere. Which one, I've no clue.