Since they were at the same rescue together, couldn't they be quarantined together?
Sorry to spoil the party but maybe you should consider more quarantine. Is there a way to at least separate Opie & Kuiper on far walls if not in different rooms. You really can never be too careful.
Be careful with Opie on the chance the green budgie could pass something to him. After all this time & work to get Opie it would be sad if the green budgie got anyone else sick. You know little about him & if they only tested for one disease I'd say some more quarantine for him would be imho the safest thing to do.
Does Kuiper still have black baby eyes? Then he would most likely be young.
I don't think in the rescue they would have been closely exposed to each other. Opie was there a long time so is likely well but Kuiper was new to the rescue with min quarantine of 1 mo. I'd just feel really bad if Opie got exposed to Kuiper & there was some latent illness in Kuiper.Since they were at the same rescue together, couldn't they be quarantined together?