Polly
The following link is for a general guide on repairing anf calibrating Jaeger/Smiths speedos. It is not specific to the Landy and refers mostly to other British marques but they are predominatly the same. Hope this may help
http://triumph.daveola.com/NOTES/Speedo_Repair.pdf
i quite like that, looks the part - but CP on a Series
who's that landy belong to ?