Ironhead Couple of engine questions

Hi there,

I got my lump back at the weekend after my mate spent the past 12 months doing sweet FA with it -



I could do some with help please. Firstly I believe I need another engine plate as I appear to have two that are the same, is that right or are they both the same shape?



Also, where the drain plug thread had stripped somebody used some of that liquid metal (pug) to fill the gap. Is it possible to buy a tap to cut a new thread or does anyone know what kind of thread it is please?

Answers to either of my questions would be really helpful, thanks.

Nick