Some dealers offer low prices with high shipping. Some offer higher prices with low shipping. Some only accept large orders (thousands of dollars). Delivery offers the risk that someone will recognize the name of the dealer sending you packages. I recommend local stores where feasible.
You’re right, they are Englehard rounds. I talked to my brother in law about it, he was some MSD (Medium Swinging D*) at Englehard before the BASF buyout. They made blanks but weren’t sold to the public, they were sold to Mints.