From the dimensions, these LEDs, when facing upwards, usually go under the name "PLCC-2" or "3.2x2.8" or something similar. They're a solid block of plastic, sometimes have a big convex lens, with two metal flap leads. If you order a "standard" one, you should be able to flex the leads so that they fit.
On a more detailed search, looks like Osram makes a LED just like that one -
LO T776-R2T1-24, Digikey (they have data sheets linked..) PN:475-1028, but they only have red,orange,green.
Things to check for: make sure the lens type is similar (most of the time they don't really have a lens, so that makes it easier), and that the voltages are compatible. Most orange LEDs have fwd voltages in the 2.x volt range, if you try to get blue or white ones with a 3V or higher rating, you'll either have to modify the current limiting resistor, or worse, get creative and add a circuit to change the drive voltage.