Hi Katie, thanks for joining the Community :) - there's currently no option to add an attachment to the estimate custom form style template but we agree that this would be a great idea. Please submit feedback for this feature by clicking the Cog > Feedback in your account, this way it'll be submitted directly to our developers who're able to implement such changes. In the meantime, you could use the 'copy' function located on the bottom toolbar of the estimate to create a new transaction and then edit any details as required.
