Kennyboy, one way is to apply several coats of gesso to fill in and cover the minor flaws. Sand lightly between coats.

I read about a clever way to make PM pumpkins (the basic shape):  Get a plastic bag of the right size, fill it with lots of crumpled newspaper until it's a bit larger than you want.

Put a small hole in the bottom of the bag and let a strong string hang out there, and run it up through the center of the bag and out the top, then pack the crumpled paper around it.  This string, when tightened later, will draw the top down and the bottom up like a real pumpkin. You may want to tie a fist-sized object to each end so you don't accidentally pull it out.  You might want to double the string, as quite a bit of pressure will be applied to it.

Then wrap the bag tightly (vertically) with string around the bag. Then take a second string and do it again, but crosswise to the first one. then twice again between the first two wraps.

When the wrapping looks right (you may have to loosen or readjust the wraps), tie a large button or round scrap of wood (etc) to that bottom string you left hanging out. Put another button on the top, then pull the string tightly, pushing down on the center of the bag, and tie it tightly so it lies flat.

Cover the pumpkin shape with strips and add a PM stem.

I hope I remember this correctly and didn't leave out some important step!

Sue