I have a L4350 , what frontend loaders will bolt up to it. It has a bf900 on it now that is wore out. Rick
The loader that should have been on it would have been a LA950A, much heavier than a BF900.
There are aftermarket option that will work well too, like a Woods loader, I have one of those and it's much heavier built than the BF900's .
What ever loader you find, you will either need to get the mounting kit or make it, the age of that tractor will make it more likely you'll need to make it.