If you're talking about the grease fittings on the bracket, any sort of grease should work fine. You're lubing up the tilt and steering bearings, which don't move a whole lot, and don't see a lot of force.
A general purpose water resistant grease, as used in trailer bearings, would probably be the easiest to source. If you can, you should match the soap carriers of the existing and new, but that''s often impossible to do (a simple way is to flush out as much old stuff as you can the first time, and stay with the same base thereafter.)
jky
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