Bulova 1940 Lone Eagle

There certainly was, the 'LONE EAGLE' is advertised as 17 Jewels.

21 Jewels would be the 'AMBASSADOR' IMO

Is the Caseback Gold or Stainless?

it is gold, the problme im running into is that I cant find an ambassador with the front engravings around the crystal.

strike 2 on the 'LONE EAGLE' ID, it's advertised as 17Jewels with Stainless Steel back.

I thought we agreed in previous discussions that the stainless backs came into vogue right around this time, and, therefore, some versions of this LE might not have had a stainless back. 

One advertisement doesn't define or limit every possibility. 

Besides that, the only ad we have is for the unengraved LE "A", which this would not be.  We don't know what features other variants might have had.

The test should be the size of the case and the crystal dimensions.

This Watch failed the first Litmus test for a Lone Eagle, it's 21 Jewels and the Gold Caseback adds fuel to the fire. 

'AMBASSADOR'

IMO

Movements can be swapped, but that change alone would not make it an Ambassador. 

The Lone Eagle and the Ambassador are not the same size.  Dimensions are necessary to tell the difference between the two.  Case and crystal dimensions.

Yes, Movements can be swapped I agree, but the odds of a 1940 Movement being swapped into a 1940 Case are practically nil.

Note the lug ends on the Watch in question, they are desigined to accept a bracelet only, the 1940 LE has lugs which are turned (grooved) to accept a bracelet or a strap.

Strike 3.

I honestly can't tell what's going on with the lugs on the subject watch.  The pins need to be removed so that we can see what is watch and what is add-on.

The purpose of the groves on the lugs is unknown.  You are making assumptions.

It would be very easy to swap 1940 movements.  Moreover, as discussed with other models--and accepted even by you--the higher quality movement could have been offered as an upgrade. 

You appear to be assuming that one advertisement--for a different variant--reveals everything there was to know about every version of this model.  That is a mistake and it contradicts every argument you have made about variants.

Again, measurements would answer the question, at least in regard to whether it is an LE or an Ambassador, as you proposed.

My gold case back measures out as an LE (crystal and case size)...and has the grooves on the lugs.

http://www.mybulova.com/watches/1941-lone-eagle-3030

Those grooves are actually apart if the spring bars. At each end of the bar it has that small circular metal tab. There are no grooves on the actual watch. The lugs end at the groove.