I picked up a pack of NOS motorcraft gaskets. Saw that they're just thin brown paper so I wasn't sure how good they'd work. So first question, do they work at all? I used one as a template and made a gasket out of modern gasket material. I haven't started the car yet, only filled it with fluid and it's leaking. Not a lot, just a small 1x3" puddle develops every time I wipe it up.

Any tricks to seal these? I have a second piece of gasket material, I could try cutting a new one, maybe I didn't do a good enough job the first time.