what is it

Hi guys,
Just got my hands on what looks like a 73 st70 can anyone help me identify type/coulour of bike because ready to start restoring it and I want to keep it as original as possible is there a listing where I can check my frame number for clues. Thanks

Hi 73st70, this is a picture of my st and it is also a 1973 and is a L reg, does yours look anything like this and mine is standard