I always "glue" the gasket to the pan, using whatever gasket sealer I have at the time. Pay particular attention to the seals. Fel-Pro (at least) has a kit that comes with their gasket set that has a trimming guide for the seal and a cheap razor knife. I always use the former, never the latter (I use a new single edge razor blade).
Here's an additional hint. I had to put an oil pump into my Corvette a few years back. To do this, I of course had to remove the pan. The new Fel-Pro gasket I got for it contained 4 headless blue plastic "snap studs". You screw them into the corner of the block, and they allow you to slide the pan up over them, and the "snaps" hold the pan in place while you insert the rest of the pan bolts. The ends of the studs have a screwdriver slot in them, so they can be easily removed and the last 4 bolts inserted. They make oil pan installation a "snap". I mentioned them here because they are 5/16" NC thread, and also fit a flathead block. I saved them and have used them on my last three flathead pan installations, and they work as well on these motors as they do on SBC's. They were not included in the last couple of flathead pan gasket sets I purchased, so I am mentioning them here. If they don't come with the gasket sets not, I would try to see if they can be purchased separately. As a last resort, I would purchase an SBC pan set just to get the studs, they are that handy. It's a good thing SBC parts are a LOT cheaper than flathead parts.
The one problem with these is that there may not be enough room to use them if you are replacing the pan with the engine still in the car. They are about 2" long and you may not be able to raise the engine high enough. Oh yeah, pan installation is much easier if you have the crankshaft in the proper position (front crank throws up).