Harry has made some very good points here. My test is extreme in all senses. I should have stated that it is an extreme magnification of the lens chart as can be seen by the small size of the slider bar on the screen grab.
The 10x angenieus lens looks beautiful to me but I have had considerable work done to it. I believe mine was built in the mid 60s. If I were you, and the lens checks out OK, I'd use it.
Here are a couple of examples of mine...
Except for the initial macro shot all other shots in this were with the 10x.
This was entirely shot with the 10x, I also shot it with my 12x optimo but did not like the 12x results. http://web.me.com/plaidass1/Site/1950.html
One thing to keep in mind is that in 4k the imagery looks quite a bit better.