I was going through my photos from a recent trip into Michigan and it appears that I took a photo of a sign with a font that has similar attributes to the LeHay font that was used on old signs in Maine. I'm debating whether this sign uses the LeHay font or not, or if MDOT ever used the LeHay font on signs at some point in the past.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Ffarm4.staticflickr.com%2F3679%2F9267444064_c71e4a3f36.jpg&hash=80003ab87c7cb7b4c6a34cd1fa38f284bae07985)
The sign in question is located on a private driveway leading to the 40 Mile Point Lighthouse off of US 23 in northern Michigan.
I don't think MDOT or their predecessor used LeHay. They had their own custom number font that is similar too, but has a few differences from FWHA font.
1. The "3" has equal upper and lower parts like the Clearview "3". The FHAW "3" has a smaller upper and a larger lower part.
2. The "4" is clipped.
3. The "5" is a circle instead of the oval FHWA uses.
4. The "6" is also a circle.
5. The "7" is clipped.
6. The "8" uses circles instead of ovals.
7. The "9" also uses a circle.