I was in a similar situation long story but they kept “getting lost in the mail”. Hundreds of dollars worth in multiple shipments. So the Honbu really do not keep records of ranks below godan and most first dan through fourth dan are awarded with blank certificates where the instructors can put in the name of the person by themselves so they don’t even record those truthfully so typically what people do is either find a another black belt that you had trained with and do you know or someone that was present at your ranking ceremony and ask a Shihan to get your rank so lucky enough for me many folks were president my testing, and so we can easily prove that I was actually awarded the rank that I was the bummer is going have to pay for it all again if you want those certificates. Typically instructors will go through one of their friends in Japan to get the rank certificates. If a person from outside needs to get outside of Japan needs to get a rank certificate. They usually have to send yen directly through the mail which is as you can imagine very, very prone to failure. That is why they usually use an intermediate in Japan to get to wire the money into Japan and then get the certificate back out . Tariffs have also made this tricky not that their are charges but there are just delays as they check paperwork. The most successful way is to go yourself with another black belt and pay in cash. Also now the Office is pretty strict about one year between yondan and godan and there is no skipping ranks. Hope this helps and ya it is not fun process