Well the more I look at this lock the more I’m drawn into liking it. Having spent an hour or so looking at the ‘lower deck’ it’s actually far more intriguing than I’d first thought, and the operation of the detector not quite as obvious as it first seemed.
Thankfully, apart from the missing detector mechanism, the lower deck is otherwise intact and undamaged, and removing the levers has revealed the smooth floating platform and split bolt stump:
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[ATTACH=CONFIG]15988[/ATTACH]
The missing detector parts might be a bit more involved than first imagined but the quality and feel of this one has already proved enough draw me in.
The lower deck bolt assemblies are in really good shape with the case stumps for the detector mechanism still showing very precise and sharp mating points, and perhaps even more of a relief, the levers are all fully intact:
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unlike the top deck levers, which have unfortunately seen a bit too much of the wrong sort of action:
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All the pics here are as viewed when dismantled, I haven’t blown out any of the muck or cleaned anything as yet.
I have though, spent hours rummaging through boxes of rusty antique blanks, and so far found one of the two that I’ll need. Not as much choice as I’d hoped, and not very fancy with the stem or flutings, but at least it’s one down one to go.
I also discovered the drill pin for the key was distorted and slightly loose in the case. A bit of fine adjustment, some light peigning, and its now central to the keyhole in the cover, and also without any wobble or play. Not a pretty sight with all the holes drilled through the cap, but at least a key blank can now enter the lock.

This Marr definitely has something about it and I can already imagine it all made good, cleaned up and serviced with two silky smooth working keys. After my original 50/50 doubts if it’d be worthwhile I’m now thinking it’s a definite yes.