In 1973 the rules were entirely reworked. For the first time the word "MONOPOLY" on the top of the rules was actually the logo. The (erroneous) history of Monopoly is included on page one for the first time (this was probably done due to the Anti-Monopoly lawsuit filed by Dr. Ralph Anspach). The rules are almost entirely rewritten bringing the language from the 30s to the 70s. Nothing much is really changed except that they are now eight pages on shorter paper and this is the first mention of the fact that you do not roll again after rolling doubles to get out of jail. The short game rules are now included and no longer on a separate sheet. There is also a forty page booklet about the history and other Parker Brothers games (the cover and first sixteen pages are reproduced below). This is also the first set of rules that mentions General Mills.
The next change came sometime in the late 1970s (probably in 1979 when the nineth U.S. Circuit Court of Appeals ruled against Parker Brothers and said that the games actual history differed from the official account). The story of Darrow on the first page of the rules no longer mentions that Darrow invented Monopoly. It simply states that he presented the game to Parker Brothers in 1934. The copyright date on the rules remains 1973. I'm not sure how long the 1970s #11 Anniversary edition with both sets of rules in it was made, but I would guess at least 1975-1979).
I don't have a lot of games from this time period so this section is a bit sketchy. I know that in 1985 the rules are unchanged from the late 1970s set. The rules in my Franklin Mint set (one of the originals from 1991 -- not pictured) remain the same but show new copyright dates of 1986 and 1991. Other than a couple of typos these rules are still identical. The next set I have that I can date is from the 1995 60th Anniversary Edition. A section on Rules Questions appears for the first time. Other than a couple sixtieth Anniversary specifics the rules remain unchanged. These rules have copyright dates of 1935, 1936, 1947, 1951, 1952, 1954, 1961, 1973, and 1994 (no mention of 1986 or 1991). The next set is from a 1995 Deluxe Edition. Like the sixtieth edition these rules have a couple of deluxe specifics but otherwise the rules are unchanged. These rules have copyright dates of 1935, 1936, 1947, 1951, 1952, 1954, 1961, 1973, 1994, and 1995. Strangely both the 60th and Deluxe rules mention Tonka as the owner of Parker Brothers even though Hasbro bought them in 1991.
1996. I need help if you can.
1997 (Rev 2 on last page). These rules remain the same as those before until you get to the short game rules. There are now five rules changes instead of three. Changes include the two properties you receive at the beginning of the game are now free. The second change is that you must leave Jail on your next turn. The third change is that Income Tax is a flat $200. This is the first set of rules I have that mention Hasbro.
1999 (Rev 3). This set of rules is out of a 2 in 1 Monopoly/Scrabble game. There are a couple of game specific changes in the "EQUIPMENT" and the "PREPARATION" sections pertaining to a wooden banker's tray. The slogan under the word MONOPOLY is changed to "Property Trading Game from Parker Brothers". The only other change I see is that they've been retyped and all broken words omitted.
1999 (Rev 4). The biggest change I see in these rules is that the slogan has been changed to "Property Trading Game from Parker Brothers". These rules have been retyped and the only other real change I see is in the legal lines on the last page.