BMW 550i Lemon

I have been working on rebuilding the engine in this BMW 550i that I purchased (non-runner timing chain had stretched). I’ve had the car for approximately a year and just completed the rebuild in March. The rebuild itself took quite a long time due to parts availability and pricing. When I took the car for its first drive it blew the serpentine belt on its second trip around the block. When looking into that I found that the main pulley off the harmonic balancer was oscillating. I continued to trace it back and found that the crankshaft was out 0.040”. This was following a grind and polish at a machine shop. This was not mentioned to myself so now the car is sitting as I have not had the time or the funds to remove the engine again and replace the crankshaft. This is where the WD40 Repair Don’t Replace would come in, I am really hoping to get this car on the road! Thanks, Josh