Up to the point on my set where I'm listening to the radio episodes that aired concurrently with the TV series (and were not a duplicate of the TV episode). The radio Thorny still is portraying Thorny and not Don Defore, which must have been weird for all involved. His Thorny does not have the lovability of Don's portrayal. In fact, you often wonder why Ozzie was friends with this jerk!
Some of the radio episodes would have been a hoot if they had been redone for TV (and maybe they were and are just part of the episodes never made available for rebroadcast/DVD/syndication)--only one episode so far was done for both (Lost Christmas Present).

The sponsors at this point were Listerine and Hotpoint.

I enjoy the radio episodes and agree with you that the radio Thorny was not as good as Don DeFore.

There is a couple other radio episodes that have been both done on radio and tv. "Be On Time" and "Invitation to Dinner".