Bruel + Kjaer 2203 service data?

Hi everyone.... I am looking for service information for a Bruel and Kjaer Sound Level Meter type 2203. The one I have has the Serial No. 887512 and so is a late version with a FET (rather than thermionic tube/valve) front end. Plus silicon transistors throughout and a couple of what look like Op-Amps. I have contacted B+K and they no longer support this model or have any service data in their archive. Someone in service-land must have data for this SLM. Please check your bottom drawer and help me if you can. Thanks in anticipation Dave