Weeping petrol on start-up

It's impossible to see the leak with pictures.

It is not unusual for gaskets to dry out on a 40 year old vehicle and cause some tiny leaks.

In general, that should not really be a problem........IF it doesn't get worse and you don't mind a whiff of gas
odor when starting out cold.

It likely is the gasket around the top of the bowl.
IF you can find the proper gasket, the fix should be fairly easy. Should be able to do it without taking anything off except the bowl.

BUT if you have never dis-assembled a carb before, I strongly suggest that you let a shop do it.

Have you tried to carefully tighten the screws that hold the bowl on ??
The key word is carefully.

Setting a float height is not a job for someone who is not familiar with the process. You have to remove the carb then the bowl. Some carbs have the setting with the carb upside down and from the float centre to the carb upper body joint line. Some have the setting without depressing a spring loaded needle tip whilst other have the setting with the carb right way up and from the float base. You will need to find out which yours is.

The method of closing the flow of fuel differs from carb to carb too. You will need to find out which yours is and follow any instructions carefully.

It isnt too hard a job if you are confident...it would pay to take lots of pictures with your phone as you go.

There could be another reason for the float level to be excessive and this is either a worn float needle/seat or dirt clogging the float action.

Good luck....oh and sometimes you can dislodge any dirt by tapping the carb close to the float valve assembly without any dismantling. Also a good carb cleaner may work ER likes Gumout....