Congratulations: I think you've got it.
And I don't mind vignetting in pinhole images. It's often a good part of the image, so don't crop to quick.
Is it possible to show us the image not cropped also?
You could also pre-flash the photo paper to control the contrast en lessen the effect of vignetting and get more details in the shadow parts. I haven't done it yet myself, but will with the new Ilford Direct Positive Paper I got from Ilford. Here is more info:
Bert from Holland