Linking actual videos would be more helpful. From what I can tell at first glance, the first set is the most promising. She's apparently said that she never showed her face on cam and only showed tits, so no. 3 and 4 are definitely out (in addition to not looking like Maimy to begin with). The body type of no. 2 also doesn't really look like Maimy (too slender).
You can usually download videos by checking the control panel. Press f12, go to network, play the video, and you'll often find a media link (usually a .mp4) which will take to where the video is being hosted. You can freely download there. Sometimes the site may just be disabling right-click "save as", so you can try downloading a Google addon called "Allow Right-Click" which will allow you to right-click on the video and save it. If none of these work, then you'll have to use a downloader and download the video that way.
Looking at #1: