Its been hard work. Not easy at all. Evening full of sweat turned into night full of curses and regrets. Spent evening taking off the back paint from my gauges, to realize, that during the process I have broken the RPM needle. After testing, the needle was just jumping in 500rpm steps. Had to take it out again, and attempt to fix it. Fixed it enough, so the needle was only getting stuck between 2-3k RPM, other than that worked fine all the way.
After that the gauges were white, but not white white as the original idea that they will fit with my Boost gauge, they were yellowish white. So the hunt for RED or BLUE LEDs began. Its not easy to find LEDs in this country, I tell you that. Tried tons of different shops and stores. And finally found some in Motor Factors. They needed a bit tweaking to fit, but here is the result:
While I was installing the RED LEDs, I probably touched something and the needle works just fine now again

So I am pleased with the result, and even the gauges are working as they should! Happy days