I have this Viking Avanti-12 which is think is Mid 70s but can't seem to find much info about them anywhere only a few forums talking about the Reynolds 531 Tubing.
These are the specs:
1. Handlebars – Vintage 90s ZOOM 170 / 6000-AL- BUTTED flat handlebars.
2. Frame Reynolds 531 Frame Tubing.
3. Derailleur – Vintage Sun Tour SVX
4. Saddle – Laser by San Marco, Blue Suede.
5. Shifters – Vintage Patent Campagnolo.
6. Wheels are Continental 700C
by DavidMason2020