[support] Testing custom maintenance page without putting the site off-line (D6)

Is there any way to test a D6 custom maintenance page without putting the site into maintenance mode? I've been tasked with creating custom maintenance pages on a D6 site that is in production and has no development/test server (I know -- bad design, but I wasn't in on the initial design). So now I have to test these without putting the site into maintenacne mode. Thanks in advance, Ken