Avocet Shoes

Looking for info on these shoes.

Original 1976-Tan/Blue-all leather & Tan/Tan-all leather- (The tan/blue looks like bowling shoes)

Model II-1979 Blue Nylon/Blue

M20 & M30 originally had a red midsole.

M20 1985- Blue/Blue with red stripe & red mid sole, Grey/Grey w/blue stripe

M30 1985-...