We went to a dinner party just last night. Several dining areas and one had bench seating on one of the rooms. Lovely room & lovely table. I was not quite the last person at the table, but had to sit in the middle. There is just not a graceful way to slip into the center. Both persons on the ends had to get up so I could be seated. Fortunately, they were very gracious, and I was very thankful I was wearing slacks and not a dress. I'd been considering bench seating too, but after this experience, I think I'll be going with chairs.

You might be able to get a local welder to repair the legs. Aluminum requires TIG welding, I think, not oxy-acetylene.

After a google lens search more in depth it led me to a youtube video of a product introduction by these guys. https://www.tem-si.com/design-switches/

If it is a Verellen - and it certainly resembles the Amelie, it is about $6000. Do what I did when I fell in love with a Baker occasional chair that was $6000. I took the picture to my upholsterer and had him make me one that looked like it. Actually it was even better because mine was completely custom including the choice of material plus the swivel pivots back into position when someone gets up from the chair. My chair wasn't cheap but it was about 50% of the cost of the Baker version.