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Hmmm...
I would say that if the 6-S-152 speaker you parted out was originally painted copper or gold as were many Zenith console speakers, then the last one you photographed is likely the right one for it. Although I find it odd that it would have one voice coil lead on one side of the transformer and one on the other, it is still usable. I think the DC resistance it shows (528 ohms in your photo) is probably correct for a 7K impedance to voice coil transformer, also.
Please measure the secondary (voice coil winding) resistance and let me know what it is. I do think the last one is probably the right one. The 921 ohm reading of the first one's primary seems too high to me.
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Ron Ramirez
Ferdinand IN
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Great Ron! Do you fingers get tired twisting that knob? That thing needs a high speed setting. (Maybe it does and you just didn't use it.)
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Hi Ron,
Here's the secondary reading... just under 1 ohm.
And yes, as rfeenstra noted your set should have that EMDE Spinner Dial, so with one quick twist of the wrist you should be half way around the dial! 
Greg V.
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Well,
Today the 8 inch Grunow speaker arrived.
This evening after work, I removed the speaker wiring harness I had made from the Philco 89B speaker and, after making sure everything was OK with the Grunow speaker, attached the cable to the Grunow speaker.
I then removed the Zenith speaker from the cabinet and installed the Grunow speaker.
Then I put the Zenith on the bench, connected the longwire, fired it up and...
It sounds great! 
So what if it isn't a genuine Zenith speaker as long as it is working well? The radio is already a mutt. I thought about trying to acquire a genuine Zenith 8 inch speaker with a 1000-1100 ohm field, but knowing that people grab those up as soon as they become available to make their own Franken-Waltons, I figured there was no point in trying.
I am quite pleased with the Grunow speaker and as a result, Greg, I really appreciate your kindness at offering the output transformer but I am going to pass. I sincerely thank you.
One more thing this radio needs: The volume control will not turn down fully. I may end up using the control from the 6-S-254 chassis...if it is any good, that is.
Other than that, this radio is good to go.
--
Ron Ramirez
Ferdinand IN
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Nice job Ron. 
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Great news, Ron!
Glad that Grunow speaker is working well for you. And not a problem regarding the output transformer. I'll just hang on to it and maybe someday I'll need it for a project.
And yes, I'm guilty of snagging a Zenith 8 inch speaker with a 1000-1100 ohm field myself to make a FrankenWalton and know they don't come cheap.
Greg V.
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Good job Ron
Grunow, Zenith, Rola, the main thing is that it's a field coil speaker that works. You've successfully rescued that Zenith and have a very handsome cabinet to boot.
John KK4ZLF
Lexington, KY
"illegitimis non carborundum"
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Thank you KCMike, Greg, and John (Eliot).
In case anyone's curious...
It doesn't look bad at all, in my opinion. Yes, it says "Grunow" on the speaker "pot", but it is a field coil speaker and it made this Franken-Zenith play, and play well.
Oh, btw, I've ordered new rubber chassis supports for this radio from Renovated Radios. The old ones are in pretty rough shape.
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Ron Ramirez
Ferdinand IN
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The Grunow speaker looks good! Mounting holes lined up perfect too I see (no reason they shouldn't have). Your Zenith blue inside cabinet still looks like new!
Regarding the rubber chassis supports, I've found if I lay a bead of clear RTV silicone adhesive sealant around the counter bore in the cabinet where the supports sit, press them in, and let them dry a few hours (or overnight) it makes sliding the chassis in a lot easier. Otherwise they are always jumping out of the counterbores under the chassis and you wind up taking it back out to put them back in place. It also makes lining up the screw holes easier too.
Greg V.
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Well done!
Steve
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Thanks Greg, Steve, Bob - much appreciated.
Tonight I removed the volume control from the 6-S-254 chassis which normally resides in the house garage, so I guess it is now officially a parts chassis. I desoldered the volume control's terminals, opened up the control and cleaned it (and its associated off-on switch) with DeoxIT, followed by cleaning the control with FaderLube.
I then put it back together and tested it with my multimeter. The control is smooth (according to the multimeter) from "off" to full open.
I'll install it into the 6-S-128 chassis in the next day or two. I think I will install new tuning condenser grommets while I'm at it. This will mean taking the dial assembly apart again, but I think it will be worth the extra effort. The grommets (and chassis supports) won't be here until Saturday.
Greg, thanks for the tip re: using silicone to hold the chassis supports in place. I will do that.
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Ron Ramirez
Ferdinand IN
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