Your Dominion Arsenals ammo was made after the war; Defence Industries only made ammo during the war. The DA 1950 that I have is all Berdan primed (big copper cap) and is corrosive and mercuric, so clean the rifle carefully afterwards (boiling water in the chamber and down the bore, wipe dry with 2 patches and then oil immediately). There ARE Berdan caps being imported, but they are a nuisance to reload with.
A lot of that 1950 DA ammo was issued to the DCRA shooters for long-range target shooting in the '60s and early '70s. It was made forr the Korean War and it was really accurate stuff.
It's definitely worth money, but I have no idea how much.
As for the LC 69, I have never seen .303 made there, would love to score even a single round.
It definitely should be reloadable, noncorrosive and nonmercuric and should use standard Large Rifle primers and it will be really decent brass. If it's anything like their .30-'06 production for that year, it will be very darned accurate, too.
Have fun!
