Here, courtesy of Bill Mullins and the Penn Pilot website, is an aerial photograph taken on May 17, 1939, showing the former site of the Pittsburgh Keystones’ Central Baseball Park.  The resolution is not extremely high here, but I think it’s possible to tell that the grandstand is gone.  You can also see some small structures in the outfield which (sort of) match buildings indicated on the 1923 G.M. Hopkins map—this may give us an idea of how far the field extended toward left and and left center fields (not far).

On the other hand, the survey maps all show Hallett St. neatly extending through the block.  While it’s hard to tell just what’s going on here, the street certainly seems less well defined.  It possible that Hallett was no more than a dirt or gravel road back in the early 1920s, and perhaps it was enclosed to form part of right field—though the ground does start to fall away right around there, so the park couldn’t have extended too far into right field without behind very eccentric indeed.

A note on other uses of the site: Williams was said to have built Central Park on a former dump.  Starting in 1925 it was supposed to have been used as a dance pavilion.  In 1961 John L. Clark wrote in his “Wylie Ave.” column in the Pittsburgh Courier of a plan to build another baseball field on the location:

According to the 1959 Geodetic and Topographic Survey of Pittsburgh the former Central Park site was divided between Dr. John S. Irwin and John Williams.

And I recently ran across a message-board mention of “the lot on Humber way (runs behind and parallel to Wylie, between Junilla and Chauncy).”  According to the writer, “They used to have tent meetings in that lot.”