Welcome to AR Slick. You might want to bring this down to the Steroid Question forum. Plenty of members down there now that can answer many of your questions. This is a welcoming forum.
I can comment to your oil based winstrol. That is nothing new. Yes you can convert winstrol to oil based. As for 50mg V day. Thats up in the air. Your buddy may be a juice head not like this board isnt full of them (me) but that amount depends on the user. Stats have to come into play. Like past cycles, size and training, diet. All history of the user. Some members here inject much more than that a day some half that. I think your friend needs to follow you here and do some research. LMR
Here is a link to a site by basskiller. This is a conversion for oil based winny. This is by our famous Harvey who you will see hanging out in the Anabolic Lab Forum.
http://www.basskilleronline.com/winny_oil.html