Does anyone know anything about this gun? Such as how many and when they were made.

Welcome to the forum A5Mag12, I' ve never heard of a Diawa A5.I would find a used Browning A5 and know I was buying quality.Sound like something from China or Japan?If you can find a Belgium Browning grab it.
Ruger Redhawk

Contrary to poppular opinion, the Brownings made in Japan have been of higher quality than the Belgian ones! The mechanical components are equal, the steel is equal OR BETTER, and the Japanese engraving is BETTER executed! The Japanese have better manual dexterity than Europeans! They do better engraving.

Eldequello, you may be right on that one there is a vast difference between a Belgian made BLR which i owned and a Japanese BLR...way better workmanship on the Jap one.

John M. Browning is probably turning over in his grave that some models of Browning' s are made in Japan.They might be high quality but still Japanese.I' ll stick with Belgium Browning' s the way J.M.B. intended it to be.
Ruger Redhawk