Heuer certainly used more than one dial manufacturer (Singer, Beyeler, others?) and in some cases across a single model. Sometimes the difference is noticeable from the front, often you'll need to see the reverse of the dial to be sure.

In fact, this is what happens for lots of components in the Swiss Watch industry, much as it does with suppliers in the automotive industry - companies spring up around the watch companies, supplying them with their specialist items. Witness how many watch companies use(d) Valjoux movements, Singer dials, Piquerrez cases etc etc etc.

With these dials though, even if they were produced for Heuer, I can only think that they would have been immediately rejected, if only for the risible reproduction of the Heuer brand itself. Even in more innocent times, when brands hadn't assumed the importance attached to them now, how the name was shown on the watch was important to these companies - text was specified as serif, sans serif, italic etc. And most of the major dial manufacturers had done at least some work for most of the major watch manufacturers, so should have a pretty good handle on how to produce, say, a Heuer shield with the correct typography inside it.

So, we stumble upon a question. If this is an existing supplier, surely they would be capable of reproducing the Heuer shield with greater fidelity than is ever shown on these waffle dials? I'm not aware of the intricacies of dial production and I imagine it's harder than sticking a Carrera dial in a photocopier and setting the copies to 125%, but you'd want a better result than displayed on these dials, I'd wager.

So if an existing dial supplier is unlikely, let's move on to another scenario. A new company, looking to make a name for itself, has some of its staff produce some dials by hand (not unreasonable for a start up, wouldn't want to make big investments speculatively) and hawks them around various watch companies as examples of their wares. I imagine the conversation would go something like this:

"Hello, I represent X, a new producer of watch dials".
"Oh hi, we're Heuer. Welcome to our headquarters".
"We've produced some sample dials for you on spec, to see what you think of our work. Here's our dial for your Monaco".
"Oh, that's interesting, I'd certainly like to take a look at tha........
...........................................................
.........................................umm?"
"Ah, you've spotted that, have you? Yes, we can't really do logos I'm afraid. But we're very keen!"
"................................................."
"I'll get my coat".

I just can't shake the feeling that, if you were using these dials to pitch for business, you'd just plain make a better effort.

Option 3. There seem to be a fair number of them, so they could be service dials. Again though, I have to feel that anything Heuer was genuinely using would be less shoddy, particularly in the representation of the shield.

So the last option is that these are some back room effort knocked out to sell some watches assembled from parts. Where the dial painter is less worried about absolute fidelity of the Heuer shield than spelling it "Heeur".

If you noticed, I presented those four options in what I consider to be increasing likelihood. So I'm leaning towards fake.