@Chm8Tin2 - strike issues such as weakness, die breaks, plugged dies, die wear, etc. are extremely common on Russian issues of this vintage owing to the currency reforms and the vast quantities being struck. They carry no premium.
The 50c Millennium looks like an Incuse and in fairly good condition, so I'd pop it into a 2x2 for protection. Worth considerably more than FV.
The round 1966 50c is 80% silver and has some nasty green gunk on it. Get some 100% Acetone from Bunnings, and soak the coin until the gunk is gone, do not rub the coin, pat it dry with a clean cloth or tissue, then put it in a 2x2.
They're pretty common, but still worth a bit of love & care.
The 2001 Volunteer Dollar is as indicated by Coaster a Rim Cud coin and IMO should also be in a 2x2.
I have 4 of these, one of which has 2 rim cuds on it, a similar one may be visible in coaster's video.
life is a mystery to be lived not a problem to be solved
Sorry to say it ,but I do not believe the 50c coin to be an incuse variety coin. In the incuse variety the cross of St George and the cross of St Patrick are recessed or incuse...and the star directly under the Union Jack is a little larger than the common variety.