As Marijn says in the comments, the
opcit documentation only ever uses
\cite with a single optional argument (one for page numbers etc. after the citation, a postnote argument).
A look at the source code of the package indeed shows that it does not support two optional arguments to
\cite. So with your current setup, it won't be easy to get the "See" in front of a citation.
As also mentioned in Marijn's comment, the
opcit package was last updated in 2006 and does not appear to be actively maintained any more. It might be a good idea to move to a more modern package. For complex citation styles like this, I'd say
biblatex is probably the best choice.
A switch to
biblatex requires a few changes to your code and a change to your workflow, but should be fairly painless nowadays. See What to do to switch to biblatex?, Biblatex with Biber: Configuring my editor to avoid undefined citations as well as bibtex vs. biber and biblatex vs. natbib for some background.
You may want to have a look at the
verbose style family
Once you've found the style that comes closest to what you want, it can be tweaked quite extensively. See Guidelines for customizing biblatex styles for a first overview.
biblatex's citation commands accept up to two optional arguments. One for a prenote and one for a postnote.