This one is one of major passed tests for GR. Infact one of the early successes of GR. Is it ? http://gsjournal.net/Science-Journals/Research Papers-Astrophysics/Download/5901 Some Extract from the paper.. .......GR correction canceled out. Vancov  subsequently solved Einstein’s orbit equations with correction numerically and has shown that it gives unstable orbits for Mercury. For heavier bodies such as stars near the central black hole of a galaxy, it leads to orbits that become superluminal and do not ever reach the origin. It is thus proven that Einstein’s Mercury correction is completely false, and fails for planets as well as black holes!........ By Roger A. Rydin.....He is a mainstream guy. Anyway I am sure, Rpenner, can surely see the maths involved. I have heard about one more paper by a Chinese guy, who found certain issues with Einstein's integration on this, I will look around and if find, I will link that too.