I know that Flymos don't exactly enjoy a good reputation for either quality or durability but I have had two Contractors - a 19" and a 21" from new in the mid 60s and they are both going strong. The 19" has been in regular rough use and as a consequence the correct yellow hood wore out and has been replaced with a blue one from a professional - hoping to find a good yellow one in the future but as most Contractors were bought for professional use I think that there are not many left! The 21" has been stored since the mid 80s until last Sunday when it was dragged from the back of the shed , given a carb and magneto clean and was up and running in a couple of hours.
These are really nice machines to come across. it's a shame they're not made that way any more. would love to find one of these myself one day.