Coin Door LEDs

Ok, I switched out the two power hungry incandescent lamps on the coin door with two bright LEDs. The LEDs are 5mm Yellow 720 mcd, available at Radio Shack (#276-350).
The LEDs are rated for 20-30 ma, so I needed a resistor. I figured it for 20 ma.
The forward voltage on the LED is 2.1, so I subtracted that from my power supply of 12 volts.
Using OHMs law:
R=E/I
R=resistance in ohms (This is what I need to know)
E= voltage (12-2.1= 9.9)
I= current (0.020)

E/I= 9.9/0.020= 495
R= 495

The closest resistor I had was 470, that figured out to be 0.021 amp (21 ma) which is just fine.

I soldered the resistor to one lead, and covered the connection with heat shrink. I then trimmed a small red wire and slid the insulation over the other lead.
I then soldered the LEDs to the coin doors lamp holder leads.
Here is a picture:
The picture is a little blurred, but the LED leads bend around to either side of the lamp holder, then soldered to the leads at the back of the holder.
The LED is positioned center of the lamp holder, where the bulb would usually be.
I then slid the holder back onto the mount.

Here is a picture with both LEDs in place. (Why cant every picture be this clear?)The LEDs can be easily removed by cutting the leads to them, then placing the regular incandescent lamps back in the holders. But if that happens, a bigger wall wart will have to be used.
With the LEDs in place, the total load (Marquee and trackball included) is 0.500 amp, the wall wart is running cool now.
The picture at the top of this post is with the LEDs turned on.
The LEDs are not as bright as the incandescent lamps, but they still have a warm glow to them. I think they will be just fine.

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