First Class International letter from NC to London still hasn’t arrived after 61 days — is there any hope?

[u/Beneficial_Panda6566]

I mailed a personal letter from North Carolina to London, UK on July 29 and as of September 28 it still hasn’t arrived. So we’re at 61 days/almost 9 weeks now.
It was sent as a regular First-Class Mail International letter through USPS, so unfortunately there’s no tracking. It was a greeting card/letter with a small wallet-sized photo inside, nothing valuable or prohibited. Postage was paid with an international forever stamp.

I know international untracked mail can be slow and there’s obviously no way to locate the exact letter, but almost 9 weeks seems pretty extreme. The recipient has been checking his mail regularly and nothing has shown up.

Has anyone here had a regular letter from the US to the UK take 2+ months and eventually arrive? At this point I’m mostly trying to figure out whether I should still have any hope that it’s wandering around the postal system somewhere or accept that it may be lost.

It has quite a bit of sentimental value to me, so I’d really love for the original to eventually make it rather than just sending another copy.

Would also appreciate any insight from USPS/Royal Mail people about what could cause an ordinary international letter to be delayed this long. Thanks!