Try the hair dryer trick. What you need to do is get 2 flat surfaces which would cover a 12". Get the hair dryer on the vinyl so that the vinyl goes a bit floppy. Press the vinyl together with the 2 flat surfaces either side of the vinyl. (i used 2 big books) Should take the bend out of the tune and make it more playable.
Advised putting the vinyl in a sleeve whilst doing this. Keeps the vinyl in good condition!
try the methods on a vinyl you dont care about much first if i was you mate