>10 uF 16 V aluminum.  Tantalum is better but a fresh aluminum will be fine.

If you're nimble you may be able to work from the backside of the
circuit board without disassembling the gauge.  If you elect to take
the board out to work on, you can Dremel the back of one rivet
(digging slightly into the case to completely remove the rivet
flange) and pivot the faceplate on the other one.  When you desolder
the mounting posts, be aware that the heater wires are passed through
holes in the post and then wrapped around it.  You have to unwrap
them before you can pull them through.  Try not to break them as they
are very difficult to tin.  Take care of the needle, it's very light
folded aluminum and quite delicate.

The faceplate will slip back over the remains of the rivet and can be
secured with a drop of epoxy on the back if you desire.  I used to
remove it and substitute a ?2-56? screw and nut, but the other works
just as well.

You can substitute a brighter LED while you're in there, but it's not
a drop-in.  The existing one is a five-volt self-blinker, in series
with a ?5.2? V zener diode.  If you replace it you'll have to replace
the zener with an appropriate dropping resistor.  RS have a
slow-blinking diffused red that can be used, or you can use a
non-blinking super-bright (I'm somewhat red-blind, so I hate red LEDs
in daylight.  I've got one in mine that will stab me in the eye and
really get my attention).

Yrs,
d