If you think to recognize here an Aria Pro 2 Thor Sound TS-600, you are not far from the truth but the headstock (typically Westone) and the position of the 3 positions switch are different. The model is unknown as Westminster, I have never seen another one.
After much research and thanks to MIJ lovers (thank you Antoine-Aubert Boissauneault from Montreal), it is identical to a Westone model manufactured by Matsumoku but it remains unidentified.
Very well made with a maple body and neck-through, rosewood fretboard.
Tuners are usual to those found on Aria Pro guitars; brass saddles and brass nut.
Electronic is the same as Aria Pro 2 TS-600: 2 very powerful humbuckers, 1 switch 3 positions, 1 varitone 6 positions / 1 Volume / 1 tone / 1 switch per pickup (in parallel or series) and an active overdrive (a switch on / off and a pot to adjust the overdrive).
Year: 1979/1980
Model: Unknown
Serial: 089024
Neck: Maple - neck-through
Body: Maple
Fretboard: Rosewood
Pickups: Humbucker x2
Electronic: Switch 3P, Varitone 6P, 1 Vol., 1 Tone, 1 switch per pickup, 1 Overdrive.
Manufacturer: Matsumoku