Watching an episode of ” Sharpe “, timed during the Portuguese campaign, circa 1809, A rifleman, carrying his weapon in a hazardous way crossing a river states ” it’s alright, Sir, I’ve wrapped it in brown paper and paraffin oil “. As the Russians didn’t refine petroleum  oils until the 1850’s, paraffin oil was unknown! It was isolated by the German chemist Reichenbach, named from it’s inability to combine with other bodies.  Also, brown paper would not be common in the backwoods of Portugal. A more obvious wrapping would have been ” mutton fat and wool”. This would have had the same effect to waterproof the action of the rifle. The anachronism is obvious.

Best wishes , I still enjoy the books and T.V. Series.

Fred E Jones