I forgot the punchline and it's driving me nuts!

Ok, although this is a question that’s been bugging me a few years now, it doesn’t really qualify for GQ. When I was a young(er) lass living in Birmingham, Alabama, I heard the following two-part joke. Ironically, I can remember every detail perfectly except for the freakin’ PUNCHLINE! Who knows this one (hoping it’s not too old and/or obscure)?
Here’s what I can remember:
PART ONE-
A man and a woman are flying in a small private jet. The man is smoking a cigar and the woman has a small poodle in her lap. The man is allergic to dogs and the woman hates cigars, and both are reaching the breaking point. Finally they reach a compromise: the man will get rid of his cigar if the woman will ditch the poodle. So they open a window (it’s a really low-flying plane, I guess), put the poodle on the wing, stick the cigar in it’s mouth and go about their business. END OF PART ONE

PART TWO-
A man has been building his own house out of bricks. All he has to do is complete the chimney and the house will be done. He measures carefully and finds that it will take exactly 99 bricks to finish the job. So he goes to the brickyard and asks the foreman for 99 bricks.
The foreman says, “We only sell bricks in lots of 100.”
“But I just want 99 bricks,” replies the house builder.
“Sorry, but it’s 100 bricks or nothing,” says the foreman.
So grumblingly, the man buys 100 bricks and takes them to the house. Sure enough, after finishing the chimney, he has one brick left over. So, standing on the roof of his new house, the man HEAVES the brick into the air as hard as he can and-

-this is where I forget the end of the joke! I think the brick and the dog meet in an unpleasant fashion before returning to the man on the roof, not sure on that though. Please, please, in my nicest voice please, can someone come up with the punchline, or at least a good likely one?
Cheers,
R-n-R

I vaguely remember this joke. The third part has something to do with a train. And the end of the joke is something about - they look on the front of the train and there is the dog smoking a cigar and holding a brick.

I’m too busy to post links, but a Google search on “poodle cigar brick” turned up several versions. Pick your favorite.

Well, I’ll be jiggered. The one damn time I don’t try a search and that’s when the motherlode is out there.
Thanks muchly!