Just thought id give an update on this for any 91 & 92 940 owners with faulty speedos.
I recently purchased one from Volvo Recycled Relics via ebay. The way this works is focussed on domestic purchases, so in an ideal world you pay for the item, send the complete cluster and they rebuild with a rebuilt speedo set to your mileage and ship back to you fully tested.
I contacted Russell who helped me by dispatching a rebuilt speedo without me sending my cluster first. They are understandably cautious about this as they lose control of the build.
It took about ten days to arrive, there was no import tax to pay and it was securely packaged in another plastic cluster. This proved to be invaluable as there was a slight dimensional variation between my cluster opening and the american speedo, so i ended up using the american cluster and speedo.
As a bonus he sent a foc clock as mine was running slow. So dispite the car currently running like crap, i finally have a working speedo, odometer, tripmeter and clock.
https://www.ebay.co.uk/itm/Volvo-199...-127632-2357-0
Hope this helps another 91-92 owner.