I hate to cast a shadow over your party (you seem very happy with your budgies) but I can't help noticing that Liv's feathers do not look right in the photo's you posted. A while back you said you were going to take Liv to an avian vet to check the feather situation out. What did the vet say?
I really hope you did get her checked out before you introduced Leggo, especially since you did not quarantine him. Otherwise you'd not only have the risk of him making her sick on top of an existing condition, but you'd also have the risk of her making him sick.
I noticed the clothes pegs and the cardboard tube (Dutch: wc rol) you pegged to the bars. These gave me a frame of reference for the bar spacing in your cage.
If those clothes pegs are the standard wooden ones (which I think they are, but correct me if I am wrong), they are about 1 cm wide. When I look at the first picture, this makes me think your bar spacing is around 2 cm.
The diameter of the cardboard tube on the last photo normally is about 4.5 to 5 cm. Your tube is flattened a bit, but it also spans only two spaces between bars. The picture is taken on an angle, so this measurement could be distorted a bit, but I still get the impression the bar spacing is 1.6 cm or more.
Bar spacing should be no more than 1.2 cm. So what I saw makes me worried for the safety of your birds. Could you please measure the spacing to make sure? I really hope I am wrong.
What are the dimensions of the cage (without the open top)? If the bar spacing is about 2 cm, the cage is less than 40 cm deep (on the second picture I counted 19 bar spaces on the short side). If the bar spacing is less than that, the dimensions are even smaller.
From you pictures I got the impression you have a cage called Big Ara (see pic below). Is that right?
If this is the cage you have, it is 54 X 34 X 68 cm, which is 21.3 inches long, 13.4 inches deep and 26.8 inches high. If this is the cage you have, check out this topic about the minimum cage size.
Have you done research on the effect of mirrors on budgies yet? If not, you might want to look into that as well.
I asked you if I was right or wrong. I asked you to correct me if I was wrong. I even said "I hope I am wrong". How is that unkind?
I provided you with information you did not have about bar spacing (which is crucial in keeping your birds safe, since they can get their head stuck if it is too wide) and suggested you look into cage sizes and mirrors. How is that unkind? I cannot imagine you'd rather not have known the spacing of your cage is too wide.
Just yesterday I provided you with information about maagkiezel, grit and the website of a Dutch avian vet. How is that unkind? You thanked me for it yesterday.
I am so sorry you did not know about the maximum bar spacing when you bought Liv her cage. That is very unfortunate. I would also be disappointed if I thought I had done the right thing and it turned out I was mistaken. That stinks and it costs money you'd rather not spend twice.
I can also understand you do want to buy a second hand cage. I did that myself. I got a Montana Paradiso 90 on Marktplaats for a very reasonable price. It is huge, in excellent condition and it was quite cheap.
Talkbudgies indeed is different from many other forums. I think that is because it has a very different purpose than most other forums. @FaeryBee includes a link to a topic about posting on the forum every time she responds to a new member. Reading that post made me understand why this forum is different.
Lastly: I am pretty sure you expected remarks about quarantine, since you said something about it in your post. I suspect you knew it is a shared view on this forum that it is necessary. It feels a bit strange to me that you expect people to ignore that you chose not to do it and be all enthousiastic about two bird buddies without quarantine.