I love to study photos of original garments to get inspiration. Some of my favourite resources are -
Extant Garments
Old Sturbridge Village
National Trust Collections - this search includes the Wade and Snowhill Collection as seen in Janet Arnold Books
National Trust Collections - this search includes the Wade and Snowhill Collection as seen in Janet Arnold Books
All The Pretty Dresses - an awesome blog that posts multiple and detailed pictures of extant gowns
Online Draft-able Patterns
Original Pre 1929 Historical Pattern Collection - great resource for drafting late Victorian and Edwardian DressesCommercial Pattern Archive - A collection of scans of pattern covers dating back to 1860, excellent for drafting