Scottparts - Scott main bearing cup replacement 

You perhaps could, but welding the case risks distorting it or causing it to crack. Also the cases are 80-90+ years old, and are of varying aluminum quality and heavily impregnated with oil, so they do not always weld. I would only ever risk welding a Scott case if it was already assumed to be scrap - if there are alternative methods I would always choose those first to save the crankcase.

Scottparts Ah I see, only weld when it doesn't matter if it turns into scrap as its scrap already. And as you say who knows what particular aluminium alloy was used :)

Fascinating,, , I might just catch one of these horses one day , good to know there's a team like U around, thanks still using imperial ✍️🤗👍