It looks like only the wheels in the back. A line of them. No marks on the front where they were ever mounted. There are a couple bolts. But they are there to hold metal in place on the inside by the blades.... You can't see the rear wheels in this picture....
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It sure did take a bite out of this mount. You can see where the secondary mount was wearing on it..
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Fixed up before the paint...
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Not meaning to sound preachy, but that is why we are always begging people to post the full mower model numbers from the tag under the seat, although simplicity put it on the side of the frame from memory.
Simplicity used to put tags on their decks as well.
Nice piece of welding but now that you have painted it I am really going to annoy you.
A weld is a casting and castings are weaker than wrought steel so you will need to put a brace over the welded area.
The heat from the weld will also have softened that side so I would run a strip of the same size steel full length on the outside .
I use old blades as I have tons of them and a small forge to flatten the curves & bends.
Now for some worse news, it looks very much like your bottom oil seal is gone on the engine.
So untill you have time to pull the engine & replace it keep an eagle eye on your oil level and the sooner the better, there is not much oil in a mower engine to start with and they all rely on splash to lube the bore piston pin & valves.
I don't have an IPL for that deck but it looks like it hangs from one side so check the lift / height adjuster to see if it could be connected to both the outside & inside of the mechanism on the mower.
If it can then refit it connected to the inside which should push the rear a little to the left.