WTR-821 Clutch Cover Fits Late A (S/N 648000 & Up), Late G (S/N 13804 & Up),  60, 620, 630, 70, 720 & 730 JD Tractors $35.00    WTR-3764 Clutch Cover Fits Late B (S/N 201000 & Up), 50, 520 & 530 JD Tractors $35.00