My Panda (1992 Fire 998cc) engine doesnt seem to have an engine number? Whaaaa? https://www.fiatforum.com/images/smilies/confused.gif
The bit where it says it's supposed to be in the Haynes manual has nothing on it except rust.

Any advice?

Emmery paper should clean it up. It should go a fair way into the block so you won't rub it off.