I use shell rotella 15w40 in the motor, with filter change is 5 qts. This oil still has the zinc in it, as oils did in 1957. (Be sure the spring is still in the oil filter cansister), many have fallen out over the years and your filter will not filter the oil properly without the spring to hold the filter aganist the motor block.
your picture shows the proper trans/differential oil sump fill hole.
It should take around 8 gals of oil, i think most put in 6 gals and let it balance out in the sumps then slowly add to full.
my tractor TO-35 will lose some oil out of the weep hole in the bottom of the transmission housing, so i only fill my rear sump to the mid level point on the dip stick with the lift arms in the down position, Plenty of oil for full operation and tractor will not leak oil.
I use GL-1 oil in the rear sumps. others may use a 30 weight oil, but the manual calls for Gl-1 oil, this oil protects the bronze or (yellow metal) bearings in the transmission. present day 30 weight oil may not have the proper lube abilitys to protect your yellow metal, new tractors do not still have yellow metal bearings in trans today.
oils may be better today than they were in 1957, but i have always used GL-1 oil and my transmission/lift system still works fine after 55 years.
If you did put kerosene in that rear sump???? i would add a gal or two of gl-1 run the tractor around some (do not use the lift) then let that oil solution drain out another day. Kerosene will clean stuff out of places you may not want cleaned out and you may have some leaks you did not have before, I would have just ran some gl-1 in the trans sump then let it drain out.
I guess i am just concerned about ruining a good working system as i ruined a good old ford car motor once cleaning it out with kerosene. it ran great before the cleaning then smoked like an old freight train after the cleaning.