Although I'm not native, I can read russian and your cards are good.
For the Ъ/ъ it's complicated (https://en.wikipedia.org/wiki/Hard_sign) but in short they do not have a fonetic sound of their own, just make the letter in front of it sound longer/harder.
On the first HUD page you have "29" instead of "39".
For the last page on SPO-15LM I recommend redacting based on this guide: