Hi all, thanks for your suggestions, when I get them home next week, I will check both the wheel bases and the serial numbers.
On another note, it looks like I have a very nice original 745 S coming. I would like to probably keep it in the original paint work. What coating do you recommend. I found an old recipe of boiled linseed oil, mineral turpentine and terebine as a hardener.
Happy to take on your suggestions.