Oil leak tohastu near oil filler screws at front ? Model m8b 3b2

Hi Fixers,
Please Help.
I am in need of some advice from anyone who has had a similar issue or knows what it is!
I recently purchased a tinny with a 8hp Tohatsu outboard.
A few days ago I took it to a welder to weld up a small crack in the hull that was leaking.
He took off the outboard, layed it down and when he finished repairing the boat he re fitted the outboard.
He had the boat 2 or 3 days.
I picked it up brought it home and parked it.
Tonight I noticed a small puddle of about 30 mil of oil under the outboard on the ground.
It is on tilt.
There is a very small square hole at the front were the what looks like the lower case meets the upper case.
I leveled the motor as if it was in the water and it doesn't drip, as soon as I tilt it it drips.
Smells like gear oil.
Has the welder wrecked my engine or has it leaked because it was laid down or something.
I assume the gear oil now needs top up as well.
Any suggestions please?
Brendan

The 8B is a 2-stroke, and unburned oil/fuel is expected in the exhaust leg. If it is black and stinky, it's normal; If it's clean, you may need new seals in the LU. That hole is a water drain.

Never just top up the LU lube, it only holds a cup or so. Just change it every 50 hours anyway. Assuming it has been a while since the water pump was serviced, drop the LU to do the wp kit, and while the LU is down, see if you need new seals/o-rings by pressurizing the LU. If it does, change both the wp kit and the seals.

Beware the age of that 8B. If it has been in salt its entire life, it may have a lot of corrosion.