These pieces are part of Ultimate Monopoly, a fan-made version of the Monopoly board game by John Izakk which combines the original Monopoly, Monopoly Super Add-on, Monopoly Stock Exchange, and Monopoly: the Mega edition. Since this is a fan-made game, it is unavailable for purchase anywhere, so it's required to make your own copy in order to play.
Since I only had the original monopoly, I made my set with resources provided online (title deeds, action cards, the board, rules, stock certificates) as well as buying a couple of used sets of the original game (for player tokens, houses, hotels, money, and dice).
The only pieces I needed to complete my set were these three, which were part of the Mega Editon (minus the taxi stand, which is an original piece)
Luckily, my school has a 3-D printer, which allows me to produce these final pieces on my own. I couldn't find appropriate models online, so I thought I would post the ones I ended up making to help others out. For Ultimate Monopoly, you need 4 cab stands, 4 train depots, and 16 skyscrapers. I recommend blue for the cab stands and train depots, and then yellow for the skyscrapers, although you could really do whatever color you want as long as they look different from your houses and hotels.
These should be printed at regular scale and turn out to be around the correct size. I included a second taxi which was the file I actually used in my print (but had to print at double the size) just in case something went wrong with the other one (that I tried to convert to the correct size).
More Ultimate Monopoly Resources:
Title Deeds: https://www.deviantart.com/jonizaak/art/Ultimate-Monopoly-Title-Deeds-Printable-425924071
Stock certificates: https://www.deviantart.com/njr75003/art/MONOPOLY-Stock-Exchange-Add-On-Set-356805444