The reel looks suspiciously close to the design of the Original Orvis Odyssey reel although the anodizing doesn't seem to be on par with that reel.
Years ago I tried (using the internet and a phone) to uncover who made the first generation of Odyssey reels and was led to a small machining shop in Central California. The business however was no longer operating or at least not under the same name.
The reel pictured shares several similarities with the Odyssey but as I said the final finish looks like powder coating. I say that because I can see where finish has worn off the pillar from where (presumably) either incoming or outgoing fly line has rubbed it off. That is not the same finish as the reels made for Orvis.
That gets you no closer to an answer but it is what I am seeing, similar but not an exact copy.
Funny. I watched a similar (essentially identical) 'prototype LH Series Saltwater fly reel' go through eBay yesterday, untouched. Relisted here.
Other than the lack of 'SDX1' on 'mine' and different handles they're the almost the same cosmetically. The SDX1 has a narrower band of cork but the ratchet and spring mech. is exactly the same.
I spent some time trying to identify this reel - the ratchet and spring seem pretty specific, and the domed counterweight is less common - but came up with a blank, so didn't bid on the UK eBay one myself.
Maybe I should have!
Hope the photos and schematic helps in your search.
The cork is opposite on an Odessey. Here is the Ahab. If I was Fin Nor I’d be twitching someone is ripping off their deign. Even the nurling on the drag knob is the same. I guess it’s tweaked enough here and there to evade copyright.
I have one of those, an SDX III that I bought new very cheaply on mail order (maybe Mullarkeys) for my first #12 rod about 20 years ago. It weighs 15.3 oz without any line or backing. I believe it was sold as Shakespeare, though there is nothing on the reel, its wooden box or the parts and care sheets to say that. The handle on mine is metal chrome. I was amused to see it given some sort of star billing by TT.
I use it for loading backing onto other reels. I wind the backing onto the SDX then wind it from the SDX to the new reel with the drag set so that the weight of the SDX tensions the backing on the new reel.