That’s awesome that you’re looking to recreate this vintage jacket. I’d love to see how it turns out for you! 🙂 I think the best thing to do is just take it one piece at a time. Start with the jacket front and back. If there’s a collar, you could see how I did a simple collar in How to Create Patterns from Existing Clothing: Intermediate Tops. It should give you the general idea. Depending on some of the details, it’s more of really experimenting, especially if you’re not taking any of the jacket apart. For instance, if the sleeves happened to be gathered at the top, you can do a basic sleeve copy and then expand the cap a bit to add more fabric to gather. Is it going to be perfect the first time? Nope, but don’t be discouraged because it’s always a learning experience and each time will be better. You’ll probably have to go back and forth a few times until you’re happy with the result. This is why it’s a good idea to make a muslin so you can test your patterns. And make sure that you baste your pieces together, that way it’s easy to take out a sleeve and try another. I do plan on expanding our series to include a jacket but probably not till later in the year.