As far as I can tell, Mark usually leaves the old versions on the server, at least the recent ones. He just doesn't leave links to them. All you have to do is type it in by hand.

Just with a quick test, I was able to go back all the way to v198, like so:

http://empeg-hijack.sourceforge.net/v198.hijack.v200b11.mk2.zImage

You might be able to go all the way back, I'm not sure. Keep in mind the format changes, too. That "b11" changes to a "b7" in there somewhere...

BTW - As a side note to this, Mark didn't even make his horizontal menus as annoying as he could have. At least his version was left justified...