I seem to have come across a bunch of Ivanko Olympic Plates.
The first image is from Ryan Bennett in Littleton (240 - 45-35-25-10-5) and listed for $300 firm on 1/11/2022. Great price for plates in good condition. $1.25/lb for Premium plates.
The second set of images is from Joey Malagon in Arvada who is selling a Russian Bar and sent pictures of these plates which he says are complete, decades old and 255# (45-35-25-10-5-5-2.5-1.25). Not for sale, but considering offers.