I used these two kits for the 7309 bucket tilt and lift cylinders on our 2120 . I didn't measure the bore carefully enough on one kit and had to exchange it for the correct one. There are several options for cylinders and seal kits on a 7309:
Replaces New Holland part # SML41555 (Not OEM.). rod requiring SML41555 Kit.
www.ebay.com
Replaces New Holland part # SML46126(Not OEM.). Replaces old part number SML43134.
www.ebay.com
As for dealer prices, $299 for a seal kit of 9 pieces for a 1-3/8" rod is extreme price gouging and would cause me to consider:
1) other brands of tractors based on the cost of parts for maintenance
2) the potential cost of damaging the many seals in a tractor by using any hydraulic oil other than exactly what the mfg recommends. Saving a $50 on a 5gal bucket of hydraulic oil would pale compared to causing a shortened life to the seals. The additives in hydraulic oils and their effects is too much to figure out if one oil is not optimal in its effect on the rubber seals.
Example of a cylinder kit (1-3/8" rod) for $299, maybe the yellow one in the picture is gold plated:
KIT, SEALS
www.messicks.com