Its possible. A SIM from that period may not contain a service centre number (they needed to be entered manually at that time) I doubt there are many people working for mobile companies who remember that.
If possible, you can manually enter the text message centre number into the phone (see O2 site) or ask O2 for a replacement SIM which will have the advantage of it being 3G)
Incidentally if the SIM number starts 8944163 then its a good idea to get it replaced anyway, as they don't work well in smartphones.