Oh interesting catch on the couch double use. For the amount of times I’ve watched every episode I’m surprised I hadn’t noticed that. The sound stage use is never as fun. Always noticed that the stage for Ransom for a Dead Man is the same as the stage used in the Short Fuse house. Even Milo Janus’ den was an obvious stage.
Cries Wolf, of course (personnel included ;)
As mentioned recently, the Google Maps of locations over on Columbophile's site is really top quality stuff: https://columbophile.com/2019/06/02/the-ultimate-columbo-locations-map/
The bid for "Greatest" Mansion in the entire series probably comes down to Arthur Kennicutt's impressive spread (The Beverly House) or Fielding Chases's ostentatious "elevator" ride and extensive property.
I like that Tudor house too in Forgotten Lady. Alex Benedict's Pasadena mansion was something tho wasn't it but I like old school. The ONE house I would love to live in tho would be Dr Mason's in How to Dial a Murder. Love Old Hollywood.