I had to put a spreadsheet together to try to tie each cash payment and each new bond with the old bonds I had.
I found this document that has the issue price of the new bonds, I could then add up the value of the new bonds along with the cash to compare with the proceeds reported on the 1099-B I received.
https://emma.msrb.org/P11599957-P11234319-P11657002.pdf
This huge document might also be of interest:
https://www.aafaf.pr.gov/wp-content/uploads/GO-Restructured-Bonds-Series-2022A.pdf
This site was helpful in getting some info:
https://emma.msrb.org/Security/Details/?id=74514L3E5
I think with that I am able to know the basis for the new bonds, but hopefully my broker is also tracking that.
I think my broker made a mistake in one case, they have my 74514L4G9 bond which was spun off from 745220EZ2 with a cost of zero. So I think they have the proceeds of 745220EZ2 wrong because it just shows the cash received.
