I don't like to know what the expression "in none too good repair" means.
It just means that something is in poor condition, or badly in need of repair. The phrase none too good is an alternative way to say not very good, but note that in some sentences the word order can be affected slightly.I don't like to know what the expression "in none too good repair" means.
For example, we wouldn't say "Tom's car is in not very good repair." (X)
Rather, we would say "Tom's car is not in very good repair."
In other sentences, the word order may not be affected. For example:
"My French is none too good." --> "My French is not very good."
Hope this helps.