HEllo,
You said everything worked great and the only problem was a leak.
Fix the leak!
The diagnosis for the leak sounds good, but the metal shavings is the question. It is normal for some fine grey deposit but not shavings. There is a good chance that the metal is from the front pump and the convertor, which caused the leak. I wood just fix the pump, convertor and new gaskets. Put the remaining money in your pocket and have a good holiday!