Get his price nailed down first to consider any decision. Since he stored it with you he may be quite reasonable. Could be in a dreamworld just as easily.

If the rods are not bent yet just using a good celane booster may keep them the same. This engine does not bend rods in europe. The only difference is the celane value of their fuel. This engine may not have been designed or have a lot of tollerance to run on our poor celane fuel. Engine is the same basically.

Since you drove it some is it using any oil yet? If so the rods may be starting to go. The number twenty head is much better than the early ones as well.