The only other thing he will sell other than trinkets is a sailor's hat (needed in the White Water Path).
There are also other things in his shop which he can't reach.
SPY FOX IN DRY CEREAL CONTROLS CODE
He swallows the disarming code to the Milky Weapon of Destruction. Udderly is the only one who knows the extent of William the Kid's deranged plan so it's essential that Spy Fox rescue him as soon as possible.