The GX345 is a pretty stout machine and should last 30+ years, However, if you wish to replace it you will need to get a 520 series minimum, a 720 is a bit stouter than your 345. The 520 will cost around 7k with a deck and blower, 720 around 11k.
Keep in mind the 300 series are much lighter duty today than your 345 is. The weak point on the new ones are the transmission and limited attachments.
John Deere 750 equipments can be expensive, there are severeal deallers to help you out if you have any questions. and you can ask for parts that you may need.
A John Deere model A holds 9.25 qts of oil.
The John Deere 850 is a compact tractor and the most recent model available is John Deere Z850A. This newer model offers more horsepower and hitching capability compared to the John Deere 850.
It will fit according to John Deere Attachment Fit Guide
The John Deere model 60 was made from 1952-1956. Here's a website full of information about the model 60...see related link...
The best place to find a John Deere Model A tractor would be on the official John Deere site. Their site would give one information on where a tractor can be purchased.
The most successful tractor model built by John Deere was the Dain All-Wheel-Drive. The most successful two-cylinder tractor produced by John Deere was the model A. The 730 was also very popular, as was the 4020.
The first tractor with the John Deere name on it was the Dain model, which wasn't very successful. It was manufactured in 1918. Between 1918 and 1923 the tractors were manufactured under the Waterloo Boy name that was already being used by a company they purchased, In 1923 they began manufacturing the John Deere Model D. They were all manufactured in Illinois.
1983 Model Year
A John Deere Model M weighs 2,550 lbs, a MT weights 2,550 lbs, and a MC weighs 3,875 lbs.
1952-1956
it depends on the model