Incredible find, were found in an estate collection I purchased. Previous owner was an employee of RCA. I have not found an exact match for these in any books or online, closest list is a DJ version with a JB prefix. These are PB 10857. Matrix numbers are machined stamped, came in plain white sleeves that are age yellowed. Records are in excellent condition, do not appear to ever have been played, there is a little dust on exposed edges and a faint small hairline here and there. These will only be shipped with insurance and signiture required at the buyers expense.Please ask any questions before bidding.