WOW !!! thanks everyone for all the pictures and advice, never thought I'd get so many responces so quick{awsome}.
I am going to weld 2 one at{inline} each arm, but now that everyone is mentioning it I'll throw in a 3rd at the middle. I'm doing this for a friend and want to make sure he is happy. I've got 5 on my tractor but I think this would be overkill for what he wants. I'm concerned as to how to weld a nice looking reinforcement on. The way the buckets angled compared to angle iron, I'm afraid it may not look that great. I'm wondering if flat stock might be easier{look better}? I was also wondering which way would be best to mount the hooks? Mounted on top would be more out of the way but also may slip chains when lose. Mounted on the front the chains would rest nicely but may be in the way???? Looks like most here prefer top mount.
When I mounted mine I put the angle iron down so that it made an upside down V. This way the hooks were still mounted on top but they also had enough of an angle that the lose chains stay in place. His tractor doesn't have enough room to do this. Tahnks again for all the GREAT advice, please keep it comming.
The regular chain grab hooks that are used on the end of chains can be used to weld on curved surfaces like the back of a bucket if a flat place can't be found. My L3650 had a HD bucket with a round pipe on the top edge and the curved chain style grab hooks wrapped around nicely for a 100% weld. No backing plate but the pipe was quite thick.
Here are my grab hooks from BXpanded. They can be removed or repositioned in seconds. Not sure if they fit on other models besides the BX models, maybe Harry can chime in if he knows if they will fit on other FEL's.