I got 50 of those 10mm, 280,000 mcd and they rock. There are 5 LCDs in one, you can see the leads while focusing on the ceiling with a magnifing glass.
Then I'd do Cristexan's idea times 2 -
File 1/4" of the 10mm LED to 6mm dia. and polish the end of the LED too! (so cut the end flat first...