The Shapiro effect is a huge non sequitur here. It is a measured effect of time delay. It is not the formula to use for gravitational redshift.
Also the Shapiro effect would cancel out for distant sources. You would be just as likely to have massive bodies on either side along the path towards us. The effect is small anyway.
The formula is Delta T = SUM (-2GM(i)Ln(1-X.R)/c^3) where M(i) is the ith peturber and X and R are unit vectors from us to the source and us to the observer.
Plug in numbers and you see the effects are in microseconds versus travel times of years to Gigayears. Anyway you would need a huge amount more mass than is observed in conjunction with a huge assymetry of this mass to have a decent delay.
But this is a moot point. It does not give a redhsift/blueshift.
For that to be the case you have to use the gravitational redshift formula which is not a logarithmic dependence.
Redshift = SquareRoot(1-2GM/Rc^2).
As you can see that drops of as 1/R from an object. Even at the surface of the Sun this is a very small fractional change.
But even this is moot. Because light from a distant source would go through these very small changes both ways. It would be slightly blueshifted as it falls down the potential of the peturber and then the same shift to the red as it leaves the potential - thus canceling out.
Also due to the 1/R relationship you would need these ridiculous amounts of massive peturbers along the line of sight even if the shift was only red. This is ruled out from many other observations.
In summary - NEVER GET YOUR SCIENCE FROM JERROLD THACKER'S GOOFY WEBSITE.
I had some email correspondence with him a couple of years ago pointing out many physics errors on his site. He was rude from the get go. He is an old crank lost in his own world of psuedo physics and just wont listen to the obvious.