I'm a direct decendant of Daniel Protzman who I believe was Lawrence's brother or cousin. Daniel is buried in Graceham, MD in the Moravian Churchyard there. Our Protzman's originated in Wittgenborn, Waechtersbach, Hesse, Germany. And...yes...my Daniel was a patriot in the Rev War and was a member of the flying column you mention. I'm a member of the NJ Sons of the American Revolution due to his service.
I have a cousin, Marion who is EXTREMELY knowledgeable about the Protzman's having written a book and traveled back to Germany to research them.If you send me your email address I will forward it to Marion and I'm sure she'd be able to help you.