Maintenance questions - gearbox, etc

i sucked up a newspaper doing a neighbor's driveway a couple weeks ago. Getting it out before an upcoming storm, I realized - it's a noma snow king I bought in '87? And it's running fine / looks good.

But the skids are worn down. The augers ARE scractched from our driveway since the skids wore down. And the scraper blade was worn. The original got flipped years ago and both sides are worn.

I bought a replacement edger years ago (a sticker talks of 2003? Finally put it on : )

overall, there's some rust but considering the age and I realized I hadn't done maintenance beyond oil changes for years, I think it looks good.

But - I realized I hadn't ever changed the gear box lube. Dusted off the manual - says it's good for life / none needed. I open the fill plug and with a sushi stick, see there there's a grease in there with gold (brass?) flakes mixed in.

I see people talk of 00 grease or 80w90 oil or gear oil or... to put in there and my head spins.

I have white lithium grease in a squeeze tube. A 'general grease' in a grease gun... but do I need to buy more / different grease for this?

Seems there's soo many types of grease - I know the 80w90 is the viscosity. the lithium talks of NLGI #2. anyone know if that's a thickness / viscosity? or how you know you can / can't use certain greases in certain places on the snowblower and general?

I wiped the white lithium over the rusting and still painted parts of the snowblower body. Can't hurt? Is there a better material to use there? And in the gear box?