Avery 5732 and 5734 mailing seal products were discontinued in 2007. The current Avery mailing seals are on 4" x 6" sheets:
5247 - 1" round mailing seals - white
5248 - 1" round mailing seals - clear
5278 - 1-1/2" mailing seals - white
5590 - 1" round mailing seals - gold metallic
If you're looking for round labels on full sheets, you can order any quantity in many different sizes and colors here:
https://www.avery.com/blank/shape/round-labels