In 1999, when I got involved Busse knives with a Logo were rare, I started selling Busse knives in January 2000, I did not see my first new factory Logo until knives were shipped to me for the 2000 Blade Show West Sept 2000, by 2002 Sterile Busse knives comprised about half of the new knives I was seeing.
So, as to whether having a Logo or not as adding to or taking away from Value relates to any particular model.
Early knives(Straight handled and earlier) a Logo adds to the value. Factory Satin finish E-models came out about the time the Laser engraving was picked up by Busse, as time wore on, having a Logo became pretty normal for more and more, a higher and higher percentage of the time.
Now I think, Logo's are designators, just another way of making a difference, giving people more personal choices, making it more likely that people can get just what they Desire in the regard.
Then you get into Numbers, or particular Logo's, some Numbers and some Logos are more popular than others.
Authenticating Busse knives has always been a case of those who know just what is what, I for instance have bought knives that may or may not be factory knives, but may be from an earlier time, the Cast Busse's that look like chipped Glass.
These knives cost enough that it really pays to know what you are doing before you buy on the resale market.