A wonderful brass lock marked 'Castell 430168'. James Harry Castell of London applied for patent 430168 in 1933 and it was granted in 1935. This type of lock was used on gas and electric meters. The small hole at the left allowed a wire to be threaded through which then had both ends locked with a lead seal. The lock could only be opened by first cutting off the wire seal. This was an additional security measure which showed if the gas/electricity meter had been tampered with. To open: Push the key in and whilst holding the key in place, slide the right half of the case backwards over the key. This is a key retaining padlock. 31.8mm wide when closed x 39.7mm tall x 9.4mm thick. 83g in weight including the key. Several hundred more keys and padlocks are available in my eBay shop.
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