I started a gallon last Nov using Jack Keller's recipe, which calls for grating the pumpkin as opposed to cubing/crushing. I didn't taste at the last racking (too afraid since the first tasting was TERRIBLE), knowing this was a longer time wine. I'd planned on adding some spices to the secondary about a month before bottling. A couple notes I wish I'd had that may help, especially if grating the pumpkin...
First, use a food processor, DO NOT do by hand!!! 5lbs of grated pumpkin flesh will leave you with hamburger-like knuckles no matter how you try. Second, when transferring to secondary, do so through several progressively smaller sieves. I ran mine through a course mesh straining bag a few times and wished I'd gone to a fine mesh and maybe even something smaller. At first racking there was about 3/8's of a gallon that needed topped up due to all the sediment.
Overall mine is an experiment. If you take it on, PLEASE start a thread and keep us updated (and tips appreciated!!)