You can't show him if he's got one undescended. That is a major disqualifying fault.
You only show in conformation if he's going to be bred, and a dog who is undescended should not be bred.
Why would you only show if breeding was an option? Isn't showing a fun competition?
My baby boy: Yoschi vom Herzbach, winner of my heart
Sire: V1-Gildo vom Herzbach SchH3, IPO3, FH, KKL1"a"
Dam: V-Fenja vom Herzbach SchH3, FH, KKL1"a"