If it's a manual pasta roller then I reckon you can get away without any grease at all. Lubrication of such slow moving parts operating so infrequently shouldn't be necessary. The gears are probably stainless steel which is pretty hard and I doubt you'd see any wear on them in your lifetime even if you make pasta with the thing every day. Grease will only trap flour and create a grinding paste on the gears which is probably worse than no grease at all.
Spanjaard have a spray-on food-grade grease though, I've seen it at places like Midas and Autozone. Otherwise commercial kitchen equipment suppliers will definitely stock it.
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