This is an example of the first variation of the 253. The tank has no model number and the positioning of the name etc is the same as their other product. It uses a fibre wheel and there is a high edge to the globe rest. The frame with this one is not shown in the catalogues with this lamp, but this combination turns up often. From the style of filler cap I would put this lamp at somewhere after 1935 but before 1938 when the level gauge was introduced.