For radios whose Serial Number begins with an "M", followed by a six digit number, you can use the following link to work out what your Keycode should be:

www.pumapeople.com/decode.php

Not a recognisable serial number, I'm afraid.

The correct serial number will begin with either a "V" or an "M", followed by a six digit number.

So, the serial number will take the form of:

M123456 or V123456, where 123456 is any six-digit number.