I think you are probably right about not beating the 1939 record by much. If we think back a year to when the negotiations over rules etc. were still under way, did Kurt not decide to walk away at one point, only to come back in when Steve had finalised the rules?
I have always gained the impression that Kurt did this not because it was a lifelong ambition, as it has been for Steve, but simply because it was yet another big challenge which presented itself.