Mercury Model 501 Component Substitutor Manual Sorry, this product cannot be purchased. $8.50 Category: Mercury Description Description For sale is reprint of Mercury 501 Component Substitutor Manual. Manual is 11 pages long, include part list and Circuit Diagram . Related products Mercury 2000 Tube Tester Updated Tube Chart $11.99 Read more Mercury 1100CK Tube Tester Assembly Manual $8.99 Read more Mercury 1101K Tube Tester Assembly Manual $8.99 Read more Mercury 1100A Tube Tester Instruction Manual with Tube Data $8.49 Read more