Ve Day Cover With Metered Postmarks--Legit?

The eagle in the meter provides a nice additional patriotic touch.

Would they have questioned his attempt to post them at a third class rate?

No doubt he made a quantity of these covers and wanted them franked as cheap as possible. The usage would be very common as unsealed Christmas cards were often sent this way, so he would not get hassled for the rate/mailing. But handing a stack of stamped 3rd class mail over the counter to a clerk would likely have gotten a dateless machine cancel. To be sure he got a "cheap date" on his 3rd class covers, he used the Mailomat, which would have dated every piece.

Thanks again, John. Good of you to share your knowledge and insight.

Ditto.