Tessar's are pretty interchangeable. Company to company, the characteristics are the same. The differences from an f3.5 to an f4.5 and from f4.5 to f6.3 are greater than any inter-company differences. The difference from non-coated to coated is greater than company to company. We could have some fun with the wine bottle in the bag type competition and shoot a lowly Ilex 8 1/2" next to a vaunted Commercial Ektar 8 1/2" and I defy anyone to actually find some difference.

The same is true of Petzval's. A petzval is a petzval is a petzval. We worry about differences between Tessar's and then we put the dullest things in front of our lenses. I probably have over 200 lenses that can make world class photographs. The problem is the photographer, not the lenses. I have a world class grand piano in my house and can't play it either.