MK3 Veglia Speedometer

My MK3 speedometer is highly inaccurate. It is a Veglia. I passed a radar sign last week which said I was doing 67 mph. The speedometer read about 82.

Anyone know if a Veglia has an adjustment screw as seen in Smith's? I don't want to take it apart if there are no "user serviceable parts inside".

Thanks.

It's a Vaguelia mines the same and will be replaced by a Smiths.

http://vintagebritishcables.com/Smiths-Speedometer-Cable-SmithsTachometer-Cable.php will service a veglia unit, as they have some veglia units they strip for parts to keep other going... i know, my veglia's are now in their parts bin...had to spring for rebuilt smith units.

So sad. I have one unit on the shelf.
Sits there collecting dust.