Pee-wee 020 fuel leak

I can't stop a fuel leak in this pee-wee 020 engine.  It is coming from the lower right (in the picture) tank to crank case bolt hole. Have replaced the gasket 2 times and still leaks the same. Blowing air into the tank using the fuel syringe produces bubbles at this location. Any suggestions on  how to stop this leak?  This engine has never run since I have had it.

Get yourself a piece of glass, place a piece of 400 grit wet dry paper on top of the glass. Place some 3 in 1 oil on the paper and carefully drag the case backside down obviously in a figure eight pattern through the oil. Continue to do this cleaning off the back of the case. Notice the sand paper marks that are being left on the back of the case. Read the marks as far as what the paper is cutting and not cutting. Once you've achieved even marks all the way across the case, your good. I highly recommend chasing the holes in the case with a bottom tap as this will enable the screws to be tightened without resistance.

One problem with extruded aluminum is that it's soft and gummy which is required to be able to be extruded. Sometimes the screws themselves pull the material of the crankcase outwards leaving a raised ridge . The gasket itself can't remedy this problem.