Ross Mk II serial number - where and what?

I gather the serial number on Ross Mk IIs is among the stampings on the buttstock. Is this correct, and which of the various stampings represents the serial number? I've looked at the MKL entry on the 1905 ***** but am still a bit confused. If not on the buttstock, where do you find the number?

Any assistance welcomed.

Thanks.

Refer to photos 74/75/76. The serial is the three digit number over the date of manufacture, plus the two letters to the right. Mk. III service rifles are similarly serial numbered.
Commercial Rosses have a serial number stamped with figures about 1/16" high, on the left side of the breech of the barrel.