Where is the head wrinkling? If it is wrinkling on the top and not the sides then the gourd may be too thin collapsed a bit. If it sounds good then that's okay, but just watch the gourd to see if it starts to flex too much or starts to crack under the pressure. When the skin is drying it will tighten WAY up and put a lot of stress on the gourd.
If you want to bring it by some day and talk gourds, let me know. I have a technique for installing skins with no wrinkles that works pretty much perfectly.
I've only got one gourd banjo kicking around. But maybe I should use this to build up my stock, as I'm finally moderately through my back orders.