Hi scoffey86, and a warm welcome to the forum. It's great to have another Scott Bonnar owner on board.
We all like to learn new things and tinker here....
grumpy has given you some good advice but as a Model 45 owner, I would like to add my two bobs worth!!
The Model 590 Diplomat was first introduced in 1976 and was Scott Bonnar's last gasp before the take over by Rover, and was discontinued at that time. This has, unfortunately, made some spare parts impossible to come by whereas the Model 45 soldiered on as the Rover 45and all parts are still available.
The rear catcher is almost impossible to source for the 590 which means all grass and debris is going to be thrown back at your feet and legs with your machine. Part of the fun when mowing with a reel mower is the smooth finish it leaves and the fine clippings make a good compost for the garden. Without a catcher this cannot be achieved.
There is also a nylon ring-gear in the rear roller that is prone to fail resulting in no propulsion; however a steel ring gear (after-market) is available, but is expensive at $132.00.
Having the reel and bottom knife-blade enclosed from the front make clearance adjustments more difficult and removal of the reel and soleplate likewise harder to do.
In fact some lawnmower repair places will not carry out repairs on them as they are labour intensive.
In my opinion, the Model 45 would be the way to go in the long term, as we have people here that have the knowledge and expertise to help step you through any repairs necessary, and owners manuals and parts lists are contained in the Manuals topic on the forum, whereas most of us have never seen a 430 or 590 in the flesh, so to speak.
Hoping this gives you food for thought and once again,
to the forum.
