RC - 1889 sounds right for the 13xxx serial - I"ll check it later against my refernces. I say nice gun and good position to have better. You might want to contact Purdey's and see what they will tell you - date of delivery and original configuration, but maybe not the original owner. If it was OE part of a trio, you can be sure it belonged to someone of means. XC might be interested to discuss with you.