I bought some marrow bones from the butcher, roasted them, ate the delicious marrow. I then decided to make broth out of it. I've made broth many times with chicken carcasses, but not beef bones from which I have already eaten the marrow out of. Anyone have experience making broth from beef bones without the marrow?
What you're proposing is similar to 'remouillage' ('rewetting'; sometimes called 'second stock'). It's a stock made from bones that have already been used to make stock.
It may not be quite as flavorful as you'd get from your first stock, but in your case, you haven't made stock with it, so any water-soluble bits that haven't been removed would still be on/in the bones. And if the bones were roasted, they'll have extra flavor from the browning of the bits of flesh that can remain on the bones.
You'll also still get flavors from any vegetables you might use, so you can make a beef/vegetable stock. Bonus points if they're also things that might have been trash -- parsley stems, the ends of onions, that sad looking pepper that you found in the back of your fridge, etc. Growing up, my mom would keep a bag in the freezer of such things, and when she had a carcass, she'd toss it all in the pot and let simmer.**
This second stock can then be used in case where you might not want the full strength stock, but as you found, you can also reduce it to intensify the flavors (but if you do that, go light on the salt)
** She'd also make seafood stock from crab shells (including legs), or shrimp shells, tails and heads; her mother grew up in the Great Depression, and you learn to be frugal.
I'm afraid you won't have much flavor in a stock made from bones with no marrow.
Stock gets that delicious flavor not really from bones, but from the marrow and connective tissue on/inside the bones. Most beef marrow bones don't have a great deal of connective tissue on them, and you've already eaten the marrow, so there's just not much left to flavor a stock.
Chiming in here, as I've done this with chicken bones instead. I used up the bone barrow and tried to create a broth from the leftover bones and connective tissue of chicken... the flavor was not as strong, nor was the aroma.
I had to be careful how much salt I added because of a blood pressure problem, but with the added pink sea salt, it brought it out more.
This would apply for any animal stock from bone marrow, the moment you take the marrow part out.