Bill, I use Tax Cut software and for line 39a, it checked that I was born before Jan 2, 1946, and it has a block for blind, and spouses info too. I may be wrong, but I think this takes the place of the older forms, and that the difference is calculated with the software.
Because I'm gonna be 76 in April, (as in over 65), I don't loose a dollar for every dollar of Social Security money either.
But, Lordy, they do make it awfull complicated to fill out.
The Hermit