My late father had 25 Zetors throughout his farming career. So we would had every model on your list nearly starting from 1977, we often had 6 Zetors at the same time. He kept some of them a long time while more were only kept 3 years as some were not what we wanted. He kept moving up in horsepower too. As he got older he stopped buying new ones and we started buying second hand 6 cylinders and ZTS. I continued were he left off, but was only able to buy 2 brand new Zetors, but of course in his time a new 10145 was only around 12000 euro, were now that would just buy you a 30 year old tractor.