Edna's brother Luke has a southern U.S. accent. It's to show the country music roots of Tommy Brown. The other day I linked to a chef with a N'awlins accent (New Orleans). Try understanding that guy and Luke will be easy, lol.

Tommy's favorite guitar could be damaged if he takes it onto an unpressurized airplane at high altitude, but he normally takes the guitar because he usually doesn't fly at a high altitude. But for the trip that led to an accident, Tommy decided he WOULD fly high and therefore left his guitar behind with Luke. He broke his habit and Columbo always suspects people who change their routine on the day of a murder (i.e.: Harold Van Wick scribbling a number down for the security guard in Playback).

Tommy guessed that Columbo was MP (Military Police), being a cop in civilian life. Columbo joked "mostly KP". KP, or Kitchen Policing was an assignment peeling potatoes for hours, cleaning dishes, mopping, whatever the cook needed. KP was usually a punishment duty, i.e. your rifle was dirty so a few hours of KP will teach you to keep it clean.

I can't answer your main question about the reasoning for canceling the Tabernacle. Did Tommy say he needed the money for something else? I wish I could help.

Hi Pete, thanks for the answers you were able to make!
That explains some of my doubts, every day you learn something new :)
With the plane I had the same way of thinking but I was not sure

Maybe this is as much of a question as a comment, but it seems to me that instead of cancelling the tabernacle entirely, Tommy could have reduced its price in a big way by reducing the scale of it. Whether it got him suspected of murder by anyone other than Luke, just plain cancelling the project would've been bad publicity for him. And keeping it going in Edna's honor would've been just the opposite thing.