By my unofficial count, just 1/3 of the 24 ballparks from 1969 were shown in the 1970 set.
The two New York parks, Yankee Stadium and Shea Stadium appeared the most. Topps liked to stay close to home.
Crosley Field was in it's final season in 1970 and this is the last Topps card to show the park.
Connie Mack Stadium was also nearing its end.
Here's a look at Fenway's Green Monster in 1969.
Lefty is sitting on the dugout steps at Washington's RFK Stadium.
This card shows the Tiger Stadium outfield.
This is the one and only card from the 1970 set that shows Wrigley Field. Pinson was with the Reds in 1967 when Topps took several pictures at Wrigley that year that ended up in the 1969 set (more details here ). The upper deck in the background is definitely Wrigley. Topps also doctored his hat by adding the blue to make the Reds hat look like an Indians hat.
The 1970 set includes four players that are wearing a Cub uniform but were with other teams.
This is the most obvious. Niekro was traded to the Padres early in the 1969 season. He was moved to the Tigers over the winter. He's pictured from 1967 or 1968, wearing a Cubs road uniform.
You'll have to take my word for it with these three, since the 1969 Cubs road uniform was a more plain gray with no piping around the neck. All three of these players were with the '69 Cubs. Selma and Phillips are older looking than past cards, so I'm saying these were taken in 1969. Nye has to be in a Cubs uniform since that is the only MLB team he played with prior to his trade to the Cardinals.
I've got 15,067 Cubs cards from 122 different brands listed on a spreadsheet. A random number generator picked five cards, one each from the past several decades.
1900s - 1970s: 1970 Topps #80 Don Kessinger This sis a really nice looking shot of the Cubs shortstop at Shea Stadium in 1969. Kessinger was in the midst of a five year All Star run. He won his second straight Gold Glove in 1970 also.
1980s: 1989 Star #7 Jerome Walton This shot come from an interesting angle, one you don't see on cards very often. It looks like the picture was taken from the bleachers. They must have been using a pretty big zoom lens.
1990s: 1993 All Time Heroes #74 Fergie Jenkins This one and done set has oddly shaped cards. The two outside parts fold over and cover the stats on the inside. You can read more about this set from Upper Deck here.
2000s: 2002 Gallery #4 Antonio Alfonseca Mordecai Brown was affectionately known as Three-Finger Brown. If not for all of today's political correctness nonsense, Alfonseca would have been known as Six-Finger Alfonseca. His extra finger did him no good during his time with the Cubs. He was just 5-6 with an ERA of 4.86 and just 19 saves.
2010s: 2015 Heritage #367 Kyle Hendricks The Cubs righty was deemed Heritage-worthy based on his 2014 rookie performance, going 7-2 with an ERA of 2.46. He slumped a little in 2015, going 8-7 and his ERA rose to 3.95.