As it says, this was built on 26 Dec 2008, the day after Xmas. It uses a high current, high gain transistor for Q2. The 2SC2334 or KSC2334 comes in a TO-220 package.
I should remind everyone that the flasher is essentially a slowed down oscillator. It can be used with a smaller capacitor to oscillate at a much higher frequency. This is not going to work with an incandescent lamp because the heated filament is too slow to respond, but it can be used to dim an incandescent lamp. The advantage is that Q2 is either fully on or fully off, so there is very little loss and very little heat in Q2.
I found another flasher, and it also uses an incandescent lamp. This is a #1850 low current light. The 1.5k limits the base current to Q2 to about 3.5 mA; Q2 must supply 50 mA to the #1850 after the filament is hot, but much more than that when it’s cold. So Q2 should have a moderate to high current gain and be able to handle more than 100 mA, I believe PN2907A, BC327 or 2N4403 should do the job adequately. Or better yet, a BD136, BD434 or SS8550 PNP transistors can handle more current and drive a brighter bulb.