Modern Vespa

Hi, I'm from India. Recently got myself a good condition 1991 LML NV 150 2-stroke for cheap. This is similar to P-150 series.
Background check on owner revealed he had tried to meticulously maintain the scooter.
My observations after purchase:
It's 31 yrs old. Gearshift is smooth, though the whole left handlebar feels a bit loose. Front brake screeches on use, Foot brake ok.
Scooter cruises silently in 35-40kmph 4th gear though after that engine noise rises enough for me not to rev past 50 kmph as I am not used to such noise on CVT scooters.
Scooter when parked inside room after a ride smells of petrol for quite a long time. Fuel cock is closed, some fuel mix leaks from the tank and collects under the seat.
The fuel meter pointer shakes a lot and I have difficulty gauging the fuel left in tank.
Some deep rust on the floorboard near pillion footrest and towards the center. Cause for concern?

Please help with some general questions:
1) how to remove and repair the deep rust?
2) whats the mileage on these things?
3) manual says mix 20ml 2T oil in 1Ltr petrol. If I rev hard (constant above 50 kmph for long rides) should more oil be premixed?
4)How to make scooter not smell too much?
5) purchased with 45000 kms on odo, what should I repair first? Tires seem ok.
6) how much intervals to inflate tires?
7) what gear oil to use and what interval for change?
8) magneto system generates AC. Can I use LED headlamp with AC?
9) how long can I ride this without break? Kms and hours before engine overheat/ critical failure? Mean climate temperature 35°C
10) What tools to purchase for self repair?
11) any more suggestions?

I am riding this daily 30 kms right after purchase. Touched nothing.

welcome!

1- take pics.

Especially of the rust. No one can really help you if we can't see the problem. Could be as simple as a rust remover or as difficult as cutting it out and welding in a new piece

2- what does the speedometer say? Or you mean the miles per gallon? That I can't help with. Someone else could chime in on that.

3- No.

4- bacon grease in with the gas! I'm joking! They smell. They're 2 strokes. They leak they smell they're perfect. You can run the carb dry by shutting off the fuel tap and letting it run until it shuts itself off. That'll clear all the gas out of the carb and with the tap kept off should reduce the smell and leaking. Unless something else is wrong like you needing to address the leaky fuel cock.

5- the brain trust here are betting at this one than I am. I'd assume at that mileage a rebuild may be in order but I'm no expert there.

6- check them everyday to be safe. It's quick and easy to do. Make it the routine to check before every ride. If they're low top them off with air.

7- this is an individual preference. I think I use 10w30? I dunno though I'd have to check.

8- yes. So long as the bulb is AC compatible. Or you can get an AC/DC converter like Koso makes and run the lights off that. That'll put out DC current. May be a bit more involved than just that. You'd have to splice into the lighting wiring to get the DC power to the lights.

9- get a CHT gauge and make sure it doesn't go above 400°F. Some may suggest even lower temps.

10- how handy are you? If you can wrench then having a bunch more would be advisable but if you can't work on the case splitting to rebuild then you wouldn't need too many tools. Clutch holder, flywheel remover and stuff like that. A 4th hand tool is very helpful for cables.

11- ride it like you stole it and have fun!

#7 : 30wt Non-Detergent oil . I change it every season on the two I ride the most.

I am attaching pictures of the rust.
Edit 1: after reading some, I found out about center tunnel and floorboard sections. Where I live, floorboard may be available but center tunnel is not.

Can I use iron grills like for windows, and weld them all around the center section, and paint, to reinforce the structure? Maybe it would look bad but the scooter might not break apart on the road...

I saw a restoration few months back, the person rode 250 kms constantly and reported an average of 44 km per liter of petrol.

Gear oil should be non-detergent yes? Since this is wet-clutch type, can I use JASO-MA2 motorbike engine oil for gearbox? If at all special gear oil is not available.
Also are they EP or Non-EP gears?
Edit 2: in the meantime I read up and learnt a lot about oil from here:
Gearbox Oil for Vespa Px 150