Freelander radio fit

Got a 2nd hand radio/cd player for my freelander genuine landrover replacement same radio is the code for new radio/cd player the last 4 numbers of the serial number with a 1 in front or after the numbers?/

I don't believe the code is incorporated into the serial number at all. It's not on the dozen or so LR HUs I've checked over the years.
You need to get the details of the vehicle the HU came out of and give them to an LR dealer to look up. Or try to get the HU re-coded from a company that specialises in such things.

cheers will do