I usually get my M3/M2/M5/P25 bulbs from eBay at reasonable cost. One thing to bear in mind with bulbs, is that even when used with leaf shutters, they don't have a constant guide number between shutter speeds (I think you have a Yashica D, Mike?). That's because they take much longer to burn than an electronic flash, so that their full outputis over a duration much longer than the 1/1000s (1/10,000s?) of the flash. It took me a while to understand that, so I thought I'd pass the knowledge around.

The flipside of it, is that you might be able to use them at a higher sync speed than the recommended 1/30s on a focal plane shutter small format camera. AFAIK, real "focal plane" bulbs were designed for large format shutters like that of the Speed Graphic, which takes much longer to complete its travel than the shutter of a small format camera.

Finally, if you want a classic flashgun for bigger bulbs (like the M5/P25), don't bother for the Graflex star wars one, they're all sold to the nerds. Get a Kalart instead, nobody knows about them, and they look nearly as cool on an old camera. It needs only two "C" batteries, which are much easier to find than the 22v of the tilt-a-mite.