I agrre with Paul's estimation of the relative value of the conservation
laws, partly because the conservation laws express the idea that value is
some sort of "stuff" or quantity comparable to energy in physics, whereas
Marx's defining remarks make it clear that it cannot be this. The "effort"
that workers put in to production is comparable to physical energy.
However, such "effort" remains in the product, whereas the value of the
product may be zero if there is no demand for it and in any case may
diminish as a consequence of competition from from more productive workers.
If we take seriously Marx's idea that "value" is a "social relation of
production" then the conservation laws do not have a clear foundation.
If the question were an interpretation which saved everything in Marx's
text as opposed to others which represented his views as mistaken in this
that or the other way, we should go for the most generous interpretation.
But that is not the case, so far as I can see. We have to choose between
intepretations which save one or other of the positions Marx took. I don't
think that the conservation of value is all that theoretically significant
(what hangs on it?) and so I opt for interpretations which take it that
Marx incorectly supposed that the conservation principles (which hold with
equal organic compositions of capital) hold generally. The charge of
"contradiction" is just posturing. Marx should, for the sake of
consistency, adjust for changes to prices of production as imputs but it is
absurd to make a charge of inconsistency in relation to a manuscript.
Shaikh, for example, shows that you can take Marx's vol III calculations as
the first step in an iteration.