The racket one is from Blueprint for Murder.

the vanish one is Myrna Loy to the excitable trumpeter in "Etude in Black".

I had the feeling "I could still get into it" would be the hardest one to find. It is actually the conclusion of a sentence within the line. Keep guessing. Great work so far.

I might be way off here... but is that when Columbo is trying to pretend he can't play golf while interviewing the golf instructor in Death Lends A Hand?

Would it be referring to the tux in "No Time to Die" when he was talking to that woman at the table, reminiscing about how he danced with Mrs. Columbo to Paul Scibelli and his orchestra?

Think Season 1. "I could still get into it".

Is it Ray Flemming asking Carol to get into an old dress from their honeymoon and she says, "I could still get into it" in Prescription?

This is a puzzler!

Eddie Albert in Dead Weight?

Well done! Eddie Albert in "Dead Weight" indeed! "Glad to be able to tell you I could still get into it." Great line.

Thanks, those are always fun. The more obscure the better!!