Nice observation there, D'Snowth. I never noticed that. I'll have to look for it. I don't recall Oliver ever adding another beam on the porch. Maybe the set directors at one point thought it appropriate to add a third one. That railing on the left hand side that Oliver kept having to fix because it would fall down was a riot. As was the doorknob that kept coming off. And the hole in the porch that Mr. Kimball's foot fell through and was sprained. That episode was really cool because Hank was in it the whole show and not just the usual 2 or 3 minute appearance.
By the way, check out this neat comment in "The Hooterville Handbook: A Viewer's Guide To Green Acres". In their chapter on the stars of the show this is the first thing they say about Fred Ziffel:
"Fred Ziffel looked a bit like a Jim Henson muppet that's seen one show too many."
Wow! Comparing Fred Ziffel with the muppets! And here I am a member of Muppet Central with the user name of Ziffel! You can't beat that!!