Found a non-auction site that has used SW4506 black follower mags for sale at $35 each. Looks like they have 15 left if any one is in need of a few.
They also had a few early 4513TSW 6 rounders listed at $50 each.
behindthelinesupply.com
They also had a few early 4513TSW 6 rounders listed at $50 each.
behindthelinesupply.com