Did well to find that masterpiece of British engineering! These are usually mega bucks new!

Top find Paul, although its not a street lighting one, (having 4 switching cams), their always handy to have for re-fits. I had a crappy Smiths timer on my central heating system, which quickly got replaced with one of these, as they run forever, and the switch contacts can be removed for cleaning up those tiny arc flash welds on the contacts.
I think H77 is the manufacture date, as mine is identical to this but the model number is S254, I have an FF1 on the face where your H77 is.

Thanks for the info Rich!

I have just had a look around Sangamos website, heres one British company that still has a spares department for all the older clocks :woohoo:

This type is generally used for switching on and Heating Units, in Industrial/Commercial unit's at pre determined times which can be adjusted by loosening the curled nut, to set a desired time switching cycles, if you can get a solar dial you can use this to operate street lighting etc, if this has a 4 wire connection/ 4 terminals with a independant switch it can be used for Part Night Lighting by connecting the Motor circuit on the Supply sidem and the switch circuit in series of the Load Side of a standard Photocell,

The H77 is the Date Code for August 1977 to find your model number you need to pull the time switch from the casing and it should be on the side of the time switch unit adjacent to the cogs, or covering the cogs.

Found it! S254

A well made time switch, heavy contacts, will never wear out nice find made in the days we still made stuff and did not import all the crap from China