Sorry I was only looking at the female couplers on the 5083e not the male tips. Male tips can be whatever thread size you need just so long as the coupler body design is the ISO 1/2 industry standard the most common thread size for these tips in an orb will be 1/2". The female couplers used on the 5083e is re45822 and does use the 51m7045 oring.
RE45822 is 22mm which can also be referenced by the adapters used like the 61m5076 (orbm 22 for coupler side, 1/2" sae flat face for the line or hose) that is commonly used when the female coupler does not screw directly into a valve as it does many times for the loader valve (this is the fitting # I used to verify the 22mm connection, we can tell which end goes where by knowing that the female couplers are not flat face but orb). For orb connections on Deere equipment I don't think you will find many examples where a xxmxxxx oring part# is used on an sae connection. The oring for conventional 1/2 orb (physical measurement of .750) is p/n r26375, the oring for conventional 3/4 orb (physical measurement of 1.062) is r29936, where as 51m7045 is pretty much reserved for the 22mm orb, we can only use oring dimensions to identify the fitting size so long as it is already known if we are in the metric world or sae world. Hope this helps.
