As I recall, vintage didnt really get going till very late 60`s, and then only as working events. First national to have a vintage class was Cross Houses in 79.
Stifling the creativity? Good point. Should it be allowed, in classes which are marketed as a demonstration of past skills and equipment? My take is this, if a part is fitted to a vintage machine, which was not available during that machines working life/ production run, that machine is no longer truly vintage, be it a plough, boat, car,
or washing machine!
Diesel engined model "N" Fordsons are a prime example,Very few were reengined to extend their working life, and those that were were specialists such as winch tractors.I know of many conversions, and every one was done as an aid in vintage ploughing,long after the tractor ceased production, and at a time when if one died, you buy two or more for the cost of fitting a replacement engine. At that time, you could buy a good running N for around £15.00.
Competitive ploughing is competitive ploughing now as it has always been. Precedents were set in bygone days which still have credence today.
Don’t forget. Hydraulics were used to operate TS86’s in the days when they were Worldstyle.