I don't know the first thing about arc welding. But the fact that it's 20th century technology makes sense. To me (again I know nothing about welding of any kind) it looked as if the maker melted iron and let it drip on to the frame. Not sure if that makes sense.
There are things about this bike that make it seem correct like the handle grip looks used-worn not made to look worn. As do the wheels. I've been around antiques all my life and know things can be made to look old.
All my online searching (even the links above) fail to show something EXACTLY like this. All of the ones online are different style. I've looked at originals and repops and nothing is like this.
On Mikes original post in the Antique bikes thread he stated he was told it's original so I'm taking that to be fact but I need to be put in touch with an expert in these. I hope Leon Dixon whom I'm going to be put in touch with - or someone else can give me a 100% sure answer of when this was made, and where. Repairs don't bother me, as long as the over-all bike is early 1800's.
Lastly while looking at the handle grip I noted it says "patented" and "size 3" no date is given for the patent however. I'm only guessing but I would think a 1850's era patent would not have a date, but a later one would? Just a guess.
I welcome any and all feedback if you know about these. Everything is another piece of the puzzle.