Well, not when this old model Nokia arrived. But I knew that cos the eBay seller stated very clearly that the phone (genuine and Made in Finland no less) was locked to the Orange network in the UK. What I didn't realise was that the service provider puts at least Two locks on their phones!
Anyway, I managed to find both codes on the Internet: yup, some of these "free unlocking services" online do work (so you shouldn't be paying to unlock a really old model like 8310 (around 2002)), just have to test a few sites out. If it charges, move to another one. There are some nice and helpful people out there :-)
So now am just waiting for the new casing (from Italy) to arrive, the old one is kinda gross and filthy; one problem with second hand phones is you never know Where they'd been ... Will post photos of my self refurbished 8310 later. I love this model. It's very nifty, stylish, basic and, obviously, durable. It's a shame Nokia lost out in the current phone war cos I think compared with Samsung and Post-Jobs Apple, this pre-Windows Finnish company was extremely creative and came up with many classic model.