occurs to me that I seem to do better for stoppers, with pressed glass, than cut - these three are examples of the former. I stuck a note to the centre bottle which reads 'Cottle', but now can't think how I arrived at that - there are some raised letters on the underside but they're virtually illegible - massive 'kick' in the base too. The right hand example does have a Reg. No., but again almost illegible though the first three digits look to be 800 which puts it at early 1935 - this problem of illegibility seems commonplace with these rather rough and ready pressed bottles.
But the bottle of interest is the larger piece - on the left - with noticeable neck rings - possibly Prussian in shape. It surprised me to find this in McConnell - under the pressed section - and which he describes as 'moule en plein' - which possibly means something like 'hot moulded glass - he dates this to 1825 - 1835, and the matching stopper is a mushroom as you'd expect for this period. If you have the first edition of Andy's book it's on page 289 - second bottle in. Picture also attached showing the matching No. 68 - in view of the lack of quality, I'd have thought it perhaps unusual for a moulded bottle to have a matching No., but it does occur here on both body and stopper - also attached is picture showing the ground/polished pontil. There seems to be some suggestion that similar bottles are from Baccarat, but there is nothing on the bottle to confirm this. This isn't entirely pressed - the neck, and both rings have cut facets, which add a touch of class, and the bottle has survived unscathed, though there is a chip on the stopper.
P.S. I've scrutinized the middle bottle again, and can just make out the Reg. No., which is 744629, which is indeed Cottle, and dated 2nd April 1929.