I had a number of responses to this query and the insulator has been varified as an M-4325
Here I am again with another help Question, but first a thank you to all that replied to my earlier post on the LOCKE Multipart, Thank You. OK, here is what I have for my questions. I have looked the Multipart guide over and over for this THOMAS insulator, and can find the style, but the measurements to not match. I compared the measurements to four listed THOMAS multipart insulators, but they all state they are a No Name with the Blue Jean Seam. This one has a very clearly incused THOMAS on the Wire Groove Crown. It has a seam but is not a blue jean seam, but rather it is a very straight line with sharp definition. The wire groove crown is exactly like the NN THOMAS M-4420 with the flat beveled face. Also of note is the step and angle of the top shell. I have placed an arrow in one of the photos showing this feature and is more defined than the photo shows (I think I had the wrong angle to emphesis this feature).
Here is the list of M Numbers that matched the style and there measurements. At the bottom is the measurements for this insulator in the photos.
M-4325 14 - 7 - 10 - 7 X 12.5
M-4331 14 - 7.5 - 10 - 8 X 13
M-4422 15 - 6.5 - 10 - 7 X13
M-4550 15.5 - 8 - 12 - 9 X 15
M-???? 14 - 8.5 - 10.5 - 7 X 13 and is clearly marked THOMAS and has a stepped upper shell. Thanks for any input to my question.