Looks like a 1977-1978 UO8 model.

A few tight zip ties ought to secure the PLUNGER-style front derailer pretty solidly.

Bottom bracket bearings can be adjusted without messing with the cottered crankarms.
Do not mess with the cottered crankarms, it is a can of worms since these parts almost never come apart damage-free without high heat applied!

The axles, freewheel and bottom bracket spindle can be oiled from each end and should then give a good length of service. Check axle bearings and headset for any signs of over-tightness.

Be gentle with this bike's brake calipers, do not heavily tighten the pivot bolts, and do not forcibly twist brake pads into alignment with the rim.

This bike's chain is much newer than the bike. Brake pads may be rock-hard, or may possibly be still-good.

I see a lot of superficial corrosion but little indication of mechanical unworthiness, so simply getting everything lubed up might have this bike riding on the road in an hour or so, from where a more meaningful evaluation can be effected.
Be sure to allow lubricants time to penetrate, and I would at least loosen up the shift levers to get some spray lube fully inside of their pseudo-ratcheting internal mechanism.

Don't trust the tires, tubes or rim strips to be in good condition without careful inspection. Turning any spoke nipples with tires still inflated invites cutting the inner tube.
Apply penetrant and wait a day before trying to tighten any of the spoke nipples.

Steel seatposts rarely get stuck like alloy seatposts do.