This circuit board has two large rectangular components. They read "MERCURY WETTED CONACT RELAY". "GD" is handwritten at the extraction end of the componenet side in pencil. There are two inspection stamps at the extraction end of the module.
Manufacturer
Scientific Data Systems (SDS)
Place Manufactured
Belgium
Identifying Numbers
Other number
119
Stamped at extraction end on component side
Other number
34 / 56789
Found on glossy silver sticker
Other number
38
Stamped in blue inspection stamp on circuit side
Other number
933354
Found on matt silver sitcker at extraction end
Other number
HGS2M-1112
Found on top of larger Belgiun component
Other number
HGSM-1006
Found on top of smaller rectanular Begiun component