I don't know about guage qualities available in the UK, but the quality of the temperature guages here is strange. The guages available from kitchen supply outlets are of infinitely higher quality than the ones available for monitoring oil temperature, with the exception of the Harley Davidson unit.
The Harley unit is of very high quality, but comes imbedded in a rubber sleeve suitable for that bike only, and is very expensive. I have yet to use a guage from a kitchen supply outlet that fogged up, was inaccurate, or failed, while I have seen countless motorcycle units fail, and often in ways I wouldn't think possible.
The guages I have used for the last 40 years have a 1" face and a needle about 6" long, and cost about ten bucks.
Chefs use them in high quality restaurants to monitor accurate cooking, and anyone who has ever tangled with a gourmet chef knows that an inaccurate guage would probably be answered with a meat cleaver to the forehead.
I guess that's why they are so accurate. Motorcyclists are easier to get along with, more forgiving, and will simply pitch a failed guage, bitch a little, and move on with their lives.
So cut to the chase and get the good guage to begin with. As for magnets, auto supply stores here sell magnetic retrieving tools that are mounted on telescoping rods very much like the old car antennas. These magnets are very powerful, and will pick up a 1/2" ratchet or a small crankshaft that has rolled under your bench. Detach that magnet and reattach it to your old dipstick, whether you have an Enfield (motorcycle) Norton, Triumph, BSA,Harley, Indian...etc.....etc.... into your oil tank, and every time you stop for gasoline, pull it out and you can see the microscopic ferrous particles you have pulled out of your oilflow. A proper wearing engine will generate these particles naturally, but flakes of any size spell trouble. As the magnet is wiped, the particles should resemble black paint, and ideally should not be reflecting like glitter. Another smart trick is to attach a donut shaped rare earth magnet to your external oil filter on your bike/car/boat/airplane/motorized uinicycle.... whatever, and transfer the magnet to the new filter when you service the machine. The particles will be magnetically trapped in the filter, and will be gone.
Automatic transmission shops and Hot Rod shops of high quality stock these magnets here...... across the pond, I am clueless, as always.
Rog....... I grabbed for that beer my friend placed out of my reach, fell out of the "workshop/closet", have assumed a new name, and am slowly reintegrating back into the motoworld.... plastic surgery scheduled, but am wearing a clown mask until my beard grows out some more.
More children wave at me on my bike now........ a cool deal. The beer tasted good, too.
