How big are the feet? (I don't know much about exotic species)
For the foot ends, you might be able to fill the feet with bondo and sculpt the legskin into the correct shape. Though I'm not sure how you'd cover the opening. This is what you have in mind, right?
As for pricing, you should charge at least $20-30 an hour plus the cost of materials. You're being asked to use your valuable time on something that's out of the ordinary. If you don't have a fixed price, charge by the hour. But anyways, good luck!