another j head question

Let the fun begin.........I just talked to the engine shop. Heads are milled and cc'ed. just need assembled and I can pick them up tomorrow. Now for the kicker!!
Pre cc was 61, after milling.........48cc holy crap. Did I just make a scrap pair of heads? Is this too much milling? It was all my fault, I didn't tell them to call with the pre cc numbers before starting the milling. I just assumed the heads were close to stock because it didn't seem like my 360 had any compression. I don't think I will be using thin head gaskets anymore:)
Also, when checking piston depth in the cylinder on stock pistons do I check the height at the edge on the higher section or the center dished section? I want to try and get a good estimate on my compression.