Thanks everyone.
I was secretly hoping that the expert concensus would be that "just the horizontal lines are enough!"
I know I was dreaming!!!

I think it'll be a bunch of stop-start, backstitch, stop start, etc!

Ah! what wouldn't I do for this project now, anyway, right!?!

While it might be a little bit cumbersome under the machine, it will be an easier task than sneaking around and meeting with my husband's friends.

He has more than I had imagined!!!!

Thank you, everyone, for confirming that I do need to do vertical lines.

Just for appearance sake, I would add the vertical quilt lines even if the batting didn't need them. I think it will give it a more finished look. That's the best looking signature quilt I've ever seen and I just adore your dog's siggy block!! :D Your DH is very much loved, that's for sure!

Thanks again, everyone.
Everyone's comments were very helpful.
I ended up quilting by machine only in the "mortar" areas, and did all the horizontal rows and between each brick.
I think it looks sharp!
It's done done done!
The birthday's on 10-10... so I'm 2 weeks ahead of schedule.

It's awesome!!! Great job!! :D

Beautiful quilt I think it turned out absolutely wonderfully....AND beautiful dog. Hopefully he/she will give it up for your DH. My beagle LOVES my quilts lol. I am making him one of his own LOL :)