Do you happen to have any interesting survey(s) for where Marxist though makes useful contributions?

Basu's A Selective Review of Recent Quantitative Empirical Research in Marxist Political Economy is a good place to start.

effectively seems to argue against the Marxist hypothesis, by showing that prices track production cost more closely than labor cost, ie, following the efficient market hypothesis.

First off, that prices track production costs is not really the "efficient market hypothesis" that all available info has been priced into financial assets. Second, the reason you think it's contradictory to the LTV is probably because you misunderstand what the LTV is saying. I'll let a critic of Marx, Ian Steedman, explain what I mean:

"… it is often assumed that a 'labour theory of value' amounts to the proposition that 'under normal capitalist conditions, the relative prices of commodities will tend to equal the relative quantities of labour-time required for the production of those commodities'. It must therefore be said at once both that under that interpretation no labour theory of value would merit ten seconds' consideration and that no serious economist has ever entertained such a theory. Neither Adam Smith, nor Ricardo, nor Marx asserted that commodities would tend to exchange in proportion to their labour contents, under developed capitalist conditions; indeed, each of them expressly denied it. In particular, Marx went out of his way, in Capital Volume 3, part II, to explain just why commodities would not exchange in such proportions. It just so happens that Marx's explanation was faulty, but what is significant, at this point, is that he sought to provide that explanation. If a 'labour theory of value' is not to be dismissed out of hand, it must amount, not to the proposition stated above, but rather to the proposition that 'the rate of profit and normal prices, under capitalist conditions, can be explained in terms of labour quantities'. It was this latter (much less restrictive) proposition that Marx maintained" - Ian Steedman, The Value Controversy chapter 1, page 13-14, Ricardo, Marx, Sraffa

So, what Tsoulfidis is doing in this paper is giving a mathematically rigorous demonstration that "normal prices, under capitalist conditions, can be explained in terms of labour quantities". If you read the paper (which is available through sci-hub) you'll see that equation (10) in the methodology does exactly this: "The above equation is a polynomial of the vector of prices...showing that prices of production can be derived starting with labour values." He goes on to demonstrate that Ricardo and Marx were basically right that "the movement of prices of production will be monotonic either in an upward or in a downward direction depending on the intensity of capital of each industry if it is above or below to the economy's average" using input-output data from Japan. The results of this input-output analysis "with respect to the measures of deviation of direct prices [prices proportional to embodied labor-time] and prices of production from market prices convey the picture of relatively small deviations and this lends support to the view that the prices of production and labour value play the role of attractors of market prices." In Marx's terms: socially necessary labor time acts as the center of gravity for market prices.