Ed. may stand for edidit, which I have seen elsewhere in connection with Foerstemann; it means the same thing, but is just the perfect tense active verb with C.E.F. as its subject.
Since it is in connection with years, I am guessing that "a. Ch." is equivalent to A.D. (Anno Domini) but stands for anno Christi, "in the year of Christ." Apparently A.D., which was standard until C.E. "the Common Era" came along, was not consistently so for a while--I have read a diploma in Latin which designated the year as "the ---th year of the Republic [(USA] and the ---th year of Salvation."