Advice asked for widthening rims on a 70 Duster

Hi all, I need some help. I have a 70 Duster, stock height. 8 3/4 rear axle. Small bolt pattern (5x4"). Current rims and tyres are all 4:
14" x 5.5 J rims with 205/75/14 tyres.
In front I am pretty confident, tyres might be 70 high instead of 75. In the back I want to go wider. Now I found someone who can proffesionally weld a ring in the rim on the outside of the rim. The side you can see. That way the backspace will remain stock. Now is my question to you: how wide can I go with the rim, get a wide tyre on it that still is a common size tyre and easy available but fits the wheel well closest to the fender possible? I calculated a bit and am thinking this: widen the rim to 7" and fit 225 tyres, but what will it look like and what height should I go for? I am thinking 70. Would love to see pics of someone who has a similar set up with good pics to be able to see how close the tyre is to the fender. Advice is appreciated too. Thnx!!!