As the question says, hopefully someone can help me - I have two different sources on French military expenditure during the interbellum period but for the life of me I can't compare the two as they're in two completely different currencies. If anyone can point a way to answer, it would be greatly appreciated.
For every 100 Francs you had in 1930 would be worth $22.70 USD in 1982. 100 Francs from 1930 would be valued at 14.70 GBP in 1982. This is raw purchasing power only and based on the 1930 Franc to USD conversion rate when the French franc was worth about four cents (25.46 to the American dollar or 3.92 cents) and then adjusted for inflation.
TL;DR
Take the total price in Francs, divide it by 100, then multiply it by 22.70 and you will have the approximate value in 1982 $.
main source: http://measuringworth.com/datasets/exchangeglobal/result.php?year_source=1913&year_result=1950&countryE%5B%5D=France
Google currency converter or Wolfram Alpha