Ed
What a beautiful crisp copy you got there!
I love seeing these "day to day" things like newspaper adverts. They bring things alive for me - more than any text book can.
As regards the comparison of prices it really is the proverbial "can of worms". Whenever I see people do it on T.V. I almost yawn and think "Yes, which basis have you used?" Because, as you say you get such differing results.
On a straight inflation basis I usually use a factor of 40 to 50 between the Nelson era and now which is very close to your 57. And in all honesty it doesn't make things seem SO expensive. However average earnings gives a very different result.
And I was told once that a multiplier based on the country's GDP (Gross Domestic Product) is THE best indicator.
Having said that I don't know off the top of my head what that is between e.g. 1805 and now.
MB