Now that all warning lights are part of the MOT i've been converting my warning light panel to LEDs. Not the unreliable bought ones, but soldering them in directly as they'll never need replacing. The solder takes to the copper strip really well.
You need to be a bit nifty with a soldering iron but i think the effort is well worth it, the colours are now bright and more vivid.
You need 5mm flat top wide angle LEDs, there's loads on ebay and they are a lot cheaper than replacement LED bulbs. I bought greens, reds and warm whites. The current limiting resistors are 680 ohms 0.6w again there's loads on ebay.
You also need to get the polarity the right way round with LEDs this isn't too much of a problem, i'll upload my diagram of the back of the panel where i have marked it on.
The indicators are a bit more tricky to do because i found that the polarity reverses depending weather your indicating right or left, again i've done a diagram of how to make it work. The silicon Diodes 1N4001 are very common on ebay too.
The red LEDs are the square ones with 4 pins, use any type you want but wide angle ones look much better as you can't see a circle in the diffuser.