Must admit, my own experience of Speedy Cables' work is less satisfactory.
They were certainly speedy enough, the price was fine and the gauge and attached temperature sender looked pristine; problem is that you can only check out the action once you've installed it and replaced the dashboard and all the other gubbins. Unfortunately, that's not a good time to find that it doesn't actually work very well, which was my experience.
The oil pressure gauge is very 'sticky' - it's either 'on' or 'off' and the temp gauge appears to over-read by about 15 degrees - heart-attack material when you're in a jam and see the needle exceeding the car's top-speed potential!
How do I know that it is over-reading and that it's not the engine actually overheating? Simple - when I stopped and opened the bonnet to check, the overflow pipe wasn't even warm and there was certainly no extra (heated) coolant in the bottle. Not wishing to go to all the hassle of pulling out the dashboard etc again to get the damn thing out to send back to them, I'm rather stuck with the problem.
Hope you have better luck.