Ride-on mower and ironing board

Years ago I bought an elderly Yardman ride-on mower as our development of the field made it ever more difficult to cut the grass with the 1964 Fordson Super Dexta tractor and 5-foot cut topper without taking out newly planted trees and flower beds.

The early years of ownership were marked by frequent trips to the repair shop, but over the last couple of years it has redeemed itself and given good service.  It's needed to have the odd bracket welded, but nothing too serious.  I have pretty much decided that it's no longer worth repair-shop bills and that I will try to discover how it works so that I can apply my limited mechanical skills to it.

I was pretty pleased a month or so ago when it lost drive and I discovered that the main belt from the engine at the front to the auto box over the back axle had popped off.  I was even more pleased when I managed to pop it back on again by temporarily removing one of the pulleys to get it back in line.  However, within a week the reason why it had popped off became clear as drive was lost again.  Metal fatigue in the side of the frame had led to one of the pulleys tearing its fixing.  You can just see daylight at the end of the arrow in this photograph - and there shouldn't be daylight visible there!

I thought that a piece of sheet steel, suitably drilled to match the bolt holes, would be enough to reinforce the side wall if placed on the outside of the frame.  As I don't do a great deal of metal work, sheet steel is not the sort of stock item I have around, but a little scavenging in the pile of stuff waiting to go to the tip turned up an old ironing board which soon gave up a piece to my angle grinder.

This doesn't make the most elegant repair, I know, but it works, and that's the main thing on a pretty ancient piece of machinery.  Perhaps I should treat the mower to some green paint to disguise the patch and self-tapping screws?