A friend of mine is looking for help with period accurate sabre fencing of the 18th century. They are working on a game set in that period, and wish to have the animations accurate to the actual techniques.

Do you know anyone who could help with this? Or where I might find an expert in this subject?

I would contact Matt Easton of Schola Gladiatoria. He is a member here, and he also runs his own forum at www.fioredeiliberi.org, and has a popular YouTube channel under the name scholagladiatoria. If he cannot directly help you, he can get you in touch with someone who can.

I will contact Easton and see if he is interested. Thank you for your help.

Matt Easton mostly studies 19th-century sabre, but you can ask about whether his students work with earlier sources like Le Marchant, Henry Angelo senior, or (pseudo?-)Roworth. I'm pretty sure he mentioned a branch of his school that prefers to work on the earlier styles of English broadsword/sabre.