Been some time since I read _Rosenberg File_ (when initially published in 80s). As I recall, R&M make case for Morton Sobell taking trips to Norfolk, VA where Rudi Abel (not sure if that is correct name) ostensibly ran spying operation out of shipbuilding firm. I think Radosh may have backed off this claim but I don't know if this is reflected in 2nd ed published following release of VENONA materials. R&M also indicate that several thousand dollar payment that David Greenglass supposedly received from Julius R was money that Soviets had paid latter couple of years earlier. Huh? How could JR have held onto this money (if, in fact, it existed) given financial straits his family was in?
Check out lengthy refutation of R&M in Rosenberg sons' (Robert & Michael Meeropol) intro to 2nd. ed of their _We Are Your Sons_. Also, *Science & Society* review of _Rosenberg File_ (I no longer have copy and don't remember author or issue but it must have been 1983-84 when first ed. was published). I read somewhere a few years ago that Morton Sobell was planning to update his _On Doing Time_ to take VENONA materials into account but I've seen no reference to it since (is he still alive?). Sobell has claimed that number of R&M's footnotes are phony.
btw: VENONA materials do not prove government case against Julius R. *If* JR was variously code-name Antenna & code-name Liberal, VENONA shows that his espionage activity did not involve nuclear secrets. This is conclusion - contra Kruschev's claim in his memoir that he heard Stalin say Soviets could thank Rosenberg for their atomic bomb - that Center for Democracy's Allen Weinstein (no leftist he) drew after going through Kremlin documents. Weinstein and several others were granted access to files in exchange for payment to group of former KGBers known as Retired Agents Association. Michael Hoover (who thinks dropping "Search for the Truth" subtitle from 2nd ed of _Rosenberg File_ is no warrant that material within is true.)