Prussian Battle Flag from Leipzig in 1813 - Landwehr? Something Else?

I spotted this flag for sale.  It appears to have been white (or gold?) with embroidery and to have hung vertically.

The seller says it Prussian and from Leipzig in 1813 but doesn't give any explanation of why?  Does this flag ring true? Which service would it be?  More details here.

28mm Prussian Napoleonic Line Infantry - Elite or Calpe?

I wish I paid attention when I painted things (probably in 2003/4. This is a definite 1813 regiment, but I can remember which.  The Flag is a bought one and the  figures are either or Elite or I think more likely to be Calpe.  I painted them using this book.