I am embarking on Franco-Prussian War and considering acquiring reference books for uniforms.
There is Osprey, but some of the books are early 1990s, and I know opinions can change over time as fresh evidence comes to light. That said the reviews on amazon are generally very good and Bruce Weigle says nice things about them in the bibliography of his 1870 rules.
I have come across a rather more expensive two-volume set published by Verlag, "FRANCO-PRUSSIAN WAR 1870-71 Uniforms and Equipment of the German and French Armies", but that is pushing £180, although probably I could find it cheaper 2nd-hand. Published 2020. Can't find much in the way of reviews.
Interested in any views on these or other sources. I am looking to make a lifetime investment for a conflict I expect to return to for more than one project (10mm and maybe 28mm skirmish later on). I don't mind parting with the cash if it's a worthwhile investment, but I don't want to spraff money up the wall.