Is anybody aware of part number or part numbers to replace the seals and o-rings inside the crowd, lift, bucket, stabilizer cylinders? Thank you

I'm not aware but all these cylinders and rods are standard sizes but there are different types of seals and piston rubbers. The hydraulic shops will know but they will likely say they want to see the old ones. If you are paying 3 times the money then ford/NH dealer should be able to pull up the part number. If you want to pay double the money then go to your hydraulic dealer. If you want to pay a reasonable price then look online, ebag, etc. If you do a giggle search on your backhoe model followed by the cylinder type/size then the online dealers will show up and you will probably find the part numbers too. Good luck. I did a few and the first thing to figure out is how to get them apart and everything is heavy heavy on those big cylinders. You will probably need to leave one end hooked up so you have the leverage to unscrew them.