Howdy, POBRatings, not for the first time I have learnt greatly from your post and I really appreciate your insights into Nuvolari. We all recall Tazio's famous stealthy chasing down of Varzi with his lights off in the 1930 Mille Miglia.
So it is with deep respect and a nice dollop of trepidation that I take a little bit of issue with your "Moss was the first really professional driver' (ie making money)". Specifically, the 'ie making money' bit. Of course, Sir Stirling to this day is on the lookout for a payday. As he's happy to tell anyone, his most lucrative year as a full-time driver earned him the modest sum of £31,000. Even adjusted for inflation, it's no more than beer money compared to Lewis's $100 million contract. So I'm only taking issue with your implication that Moss being 'professional' was just about the dosh.
I'm way too young to recall this directly but I've read a bit -

- and it appears that Moss frequently had the mickey extracted by his peers and the British press (they hadn't invented the word 'media' back then) for the way he went about racing. Important to recall that in the early 50's, the old "Gentleman vs Players" attitude was still strong. The British racing scene was largely dominated by the Brooklands crowd with their shooting sticks and leather patches on their Burbery tweed jacket. So this young upstart Moss doing things like turning up in a starched white overalls with body belt and BRDC patch on his chest when his rivals were wearing civvies with their trousers tucked into their socks, his appointing of the first ever full time manager in motor racing in 1952 (Ken Gregory), his seeking endorsement contracts... all these things were seen as some combination of vulgar and counter to the spirit of 'The right crowd and no crowding' philosophy.
His perceived craven professionalism - the word was not a compliment back then - was perhaps best illustrated with Mike Hawthorn's deliberate and over the top 'jumping the start' in the Le Mans style start in the Goodwood TT one year. Moss yelled out 'You lovely individual Hawthorn' as the starter's gun fired and Mike Hawthorn, bow tie and all, got away last after helplessly rolling around beside his car clutching his sides laughing. The British press got a lot out of that example of a gentleman unsettling a player.
But there is a certain incongruity in this. Moss was all professionalism but after his Vanwall period when he lost the WDC he little by little changed to the point where it was all about winning - but just as the underdog.
So... Nuvolari was serious about winning but Moss was, I believe, to surround himself with all the accoutrements of 'professionalism'. The first of a line that later included the likes of Stewart, Lauda, Senna and Schumacher.