The Gold Medallion of Crofton Park

Jack writes:

I found this St Christopher medallion at Crofton Park Station , this is real sentimental jewllery. There is an inscription on the back. I tried my luck to advertise it at Crofton Park Station but was not allowed to do it, so here I am to try my luck to find his/her owner. Please email me if you are the owner and can tell me what the inscription on the back is.