It is just the in-feed from the casting process for the molten ali to pour into the mould, that is all. The casing cannot come apart there. The feed tab will be snapped off as the casing is cooling and they don't bother finishing it off.
Nobody has perfect identical castings - unless of course you are looking at Japanese motorcycles? I remember the first time I pulled a Big 5.7 V8 out of a Yank car - I had only really previously rebuilt BMW,Mercedes and VW/Audi engines - I couldn't believe how basic,unfinished and rough the American power units were finished and the story was even worse inside the cylinder heads! I then realised that was why if they wanted a car to go faster they just stuck another V8 in with 7.2 litres
Hahaha - never forget chap that it's Italian! I owned an Italian rifle many years ago when I lived in Spain - wild boar laughed at me and after a while didn't even bother to run off when they heard me coming? It was without doubt the worst gun ever made,regularly fell apart and constantly jammed instead of ejecting spent casings.The crafty old boy who sold me the piece of shit said it had been in his family for years? I can only think they must all have bee vegetarians or they would of 100% starved?
A sample size of one is perhaps not statistically significant. The fact that a number of folk on here have seen similar ought to reassure you though
Looks fine and to be honest how can u think it bad it just casting how may duc owners would love that finish. Lots me thinks as it look like it still painted and the paint not disintegrated. Tremendous effort that it still got paint on for a 16 year old engine
My original 749 engine was rough like that. Since i have used it in the rain though the flaking paint is now like an urban camouflage, there is always that option to cover it up?
