Does this MKU67 sound right?

There's no easy way.  That's why tube dealers who are actually trying to make money don't bother.  The deeper you go into testing, the more problems you find and why would they sell only half their tubes when they can sell them all at a set price and just take returns from buyers who notice problems?  

  I started out by doing exactly what you are, by listening to them one by one and picking out the good ones.  This only became a business because many friends, and friends of friends, and their friends, also wanted good tubes, to the point that it became full time work 10 years ago and I had to take the screening process to another level (or three).  The best advice I can give to audio engineers is not to invest too much into equipment or time because there's aspects that go far beyond anything basic gear can evaluate.  Plus, without many samples to compare, you don't really have a good basis for evaluation. Further still, the market is getting more saturated with other people's rejects with every passing year.  So, don't invest a lot up front and expect it to be smooth sailing.  Knowledge is a huge part of it.  Like most types of antiques, it's easy to get burnt.  The people who know how to find the good stuff aren't selling it cheap.  Most of the "tube collections" people try to sell me are just low quality tubes they picked up on ebay as "NOS" but, sadly, there's usually very little of value in them.  If you do it yourself, get them cheap (if you still can) and have reasonable expectations.  

  When I started, I had several hundred dollars in testers and thought I was ready to go.  It didn't take long for me to realize how inaccurate most vintage testers are and how ineffective they are at detecting certain issues.  Tubes can behave quite differently in different circuits (for those that don't know, there are many different ways to run a tube and it's not always the same from one piece of gear to another), and there are quirks inherent to all tubes that you won't understand without years of experience.  For instance, a Sylvania 12AX7 will often still test "better than new" when it's aged, noisy, and dying.  But, a never-used RCA 12AX7 might test "bad" even though it's essentially new with a full life ahead.  A tube might scream with microphonics in one type of gear but not another.  Etc, etc. There's reasons for all these things but I'd have to write a book to explain it all.  And, I'd have to revise it every year with the new things I learn.