Good thread, but the historical summary is slightly flawed
1961 - An enlightened Christian who accepts a blood tranfusion or a banned blood product or donates blood should be viewed by the congregation, "rebellious opposer and unfaithful example to fellow members of the Christian congregation he must be cut off therefrom by disfellowshipping." (Watchtower 1/15/61, p. 63-64)
Elevating the transfusion medicine taboo to a "Disfellowshipping" offense was a big change.
1966 - "...the taking of blood is just as despicable to you as cannibalism. Think of eating of the flesh of another human creature! It is shocking! Is drinking human blood any different? Does bypassing the mouth and putting it directly into the veins change it? Not at all!" (Watchtower, 7/1, p.401, par. 7)
Not a change from a previous position. The original argument had always been that transfusion is neither physically, nor morally distinguishable from eating human blood.
1978 - Watchtower Society mentions medical advances of separating blood into primary components (red cells, white cells, platelets, and plasma). Because of these medical advances, a Jehovah's Witness is now allowed to take blood serums made from "a small amount of a blood derivative." (Watchtower 6/15, p. 30, 31)
Not a change from a previous position - Serums were first allowed 20 years prior to this, in 1958. (cf. W58 9/15 p. 575) There was a brief reversal in the early 60's and they were allowed again in 1964 (cf. W64 11/15 p.682)
1982 - "However, Witnesses' religious understanding does not absolutely prohibit the use of components such as albumin, immune globulins, and hemophiliac preparations; each Witness must decide individually if he can accept these." (Awake! June 22, p. 22)
Not a change from a previous position. Clotting factors were declared to be a "gray area" in 1978. (cf. W78 6/15 p. 31) The use of other plasma proteins by JW's had been going on for decades at this point.
1982 - "Witnesses believe that blood removed from the body should be disposed of, so they do not accept autotransfusion of predeposited blood. Techniques for intraoperative collection are objectionable to them." (Awake! June 22, p. 25)
Not a change from a previous position - Autologous transfusion and storage of blood were forbidden 23 years prior to this, in 1959 (cf. W59 10/16 p. 640)
1989 - The Watchtower Society appears to open the door so that storing one's own blood is permitted. Though not mentioned by name, it is implied that use of scavenging techniques are a "matter of conscience." (Watchtower 3/1/89, p. 30, 31)
Apparent misunderstand here about what a Cell Saver does. Blood salvage machines are not considered "storage" by Witness definitions of the term. (i.e. If the procedure can be looked upon as a continuous circuit, regardless of whether the blood is moving or not, the blood has not been stored.)
1995 - The August 1 Watchtower, p. 30, shows for the first time that it is acceptable to store one's own blood for later use. It says it is, "a technique that some Witnesses may find unobjectionable under certain circumstances."
Not a change from a previous position The article was talking about treating Witness and non-Witness patients. It refers the reader back to the March 1, 1989 issue of The Watchtower for a definition of those "Certain circumstances" as they apply to JW's
1996 - The Watchtower Society now contradicts themselves saying: "This means that we must not take into our bodies in any way at all other people's blood or even our own blood that has been stored." (Brochure called "What Does God Require of Us?" p.25)
Not a contradiction.
2000 - In April, Circuit overseers in the United States receive a letter instructing them to inform local bodies of elders not to disfellowship anyone who accepts blood transfusions. If their conduct becomes known and they are deemed unrepentant, they will be considered to have disassociated themselves.
2000 - In June, the Watchtower says, "...when it comes to fractions of any of the primary components, each Christian, after careful and prayful meditation, must conscientiously decide for himself." This lays the foundation for members to accept oxygen carrying RED CELL (hemoglobin) solutions. (Watchtower 6/15/00, p. 29-31)
2004 - The June 15th Watchtower expands on the June 15, 2000 article. For the first time, the rank and file Jehovah's Witness learns that the single largest blood component which are RED CELLS (hemoglobin) is now permitted as a matter of personal choice.
Current Understanding - "...when it comes to fractions of any of the primary components, each Christian, after careful and prayerful meditation, must conscientiously decide for himself." The Watchtower June 2000, p. 29-31; June 15, 2004, p. 29-31