yes, a boiled egg in the middle of the meatloaf.

i've heard of people doing that (it adds more protein while cutting down on the amount of actual meat in the dish) but i've not done it myself.
I put beaten eggs in the meatloaf, but hadn't thought about putting a boiled egg in there... I think I might try it, since I always have a ton of eggs (I have chickens.)
OK, this is embarassing. This thread is the first time I realize it's not normal to put a whole egg in. I am in my 30s but the only meatloaf I've ever had is my Mom's and that is how she makes it. Actually, the egg is my favorite part, it's all cooked with meat juices and is extra-yummy.
It's not that it isn't NORMAL, it's just regional differences. I grew up having "porcupine balls" which are balls of meatloaf mixture with rice in them, cooked with BBQ sauce on them. Or stuffed bell peppers which also had meatloaf mixture.

Eggs in the meatloaf just weren't something I grew up with. :)
I really want that cookbook. Internetarchive.org has "275 wartime recipes", but it's just not the same.
Have you read "A thousand ways to please a husband with Bettina's Best Recipes"? It's available on Google books, and is hysterically awesome.
OMG, makes me think of the Bones ep where Booth revealed he didn't like meat loaf because his mom would put hardboiled eggs in it and tell him they were human eyeballs.