The oiler's in my spindles in my 26 are threaded. Where can I order new oilers for it and what would the part number be?
Those were made for grease fittings, they should be 1/8" npt and you can get them at any auto parts or Ace hardware.
Early (pre '15) spindle & tie rod bolts were threaded for brass twist oilers - you might just be able to use the correct press-in flip top oilers in those.
McMasterCarr has oilers with a 1/8 pipe thread which should fit your kingpins. They also have 1/4 pipe thread oilers. Oil would be better than grease IMHO.
Grease from the top will only lubricate the top bushing while oil will drop down to the lower one too.
If you still wants grease, you can drill and thread a hole in the middle of the spindle body for a second zerk - that'll get some grease to the lower bushing too.
We have the brass oilers part # T-3817