I have one of those. The tail on it is different from either of those. It's proportioned more like the thinner one, but not as angled downward. It's one of my very best shavers. Just magnificent, though it's deceptively large. Photos make it look 6/8 or so, when in fact it's a full 7/8. The blade is very long.
Lummus lists it as 1830, but I've seen others in the exact same style with the same scales, but different stamps entirely. Mine also is 'W. Greaves & Sons' on the blade with 'CAST STEEL/WARRANTED' on the tang.
You'll probably be pleasantly surprised with the honing. Just put a layer of tape on. Mine took to the rock like a duck to water.
Edited to add a picture!
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