I fought the fight with my '50 Chevy COE and I thought I won. No gaps or creases and it looked good. A year later the cardboard headliner had shrunk and I had gaps like Dusty has posted above. I give up.
Kent

1937 Chevy 1/2 ton
1942 Chevy 1/2 ton
1947 Diamond T Model 509
1951 Chevy 1/2 ton
1950 Chevy COE Model 5700 ~ "Barney" ~ And more pix