Watso- "silverside Roast" is different to "Corned Silverside"- the recipes for which you consulted on the Net- Silverside Roast is the piece of beef which has not been passed through the salt solution to "corn'' it ( or' Pump' it as it used to be called)resulting in a salty taste to the beef. I think in the U.S.A it is called "salt beef".
The piece you bought would seem to be the beef that is usually roasted for a traditional roast dinner with roast veggies etc. You would not usually use vinegar, sugar etc nor cook in simmering water- Even so, you can actually cook the unsalted piece in the simmering water which results in a milder flavour than a piece of corned beef.(Although I don't know how the addition of the commercial marinade will turn out).
You can also cook a leg of lamb like this instead of roasting. Butchers used to sell legs of "hogget'' or elderly lamb & run it through their salt solution while you waited. It resulted in a delicate lightly salted flavour often superior( & cheaper ) than ham.
Incidentally anyone noticed the enormous legs being called "lamb" in the supermarket butcheries?They must be almost mutton or "hogget" as we so genteely used to call it. This was probably as a reaction to the poverty of the early pioneers whose diet was usually the cheaper mutton or corned beef which kept better than fresh beef when they could afford them. All too often their diet was mostly damper & golden syrup. Let us know how your roast/corned silverside tastes. I see I have introduced several new topics into this post. Pl. forgive me on account of"silverside" & "corned beef' resulting in a whole stream of memories of early pioneer days- OOps there I go again.
