@Anonymous_ I see at https://sa.www4.irs.gov/ola/payment_options/make_payment that I could make a payment for an amended return for 2019-2022, but those amended returns don't exist yet. So it seems to me that if I am really going to file amended returns I should just go ahead and do it and let TurboTax calculate the penalties and interest due for each year and pay everything when I submit the amended returns? If so, the question for me is "how long does it take to file an amended federal return with TurboTax?"
$2,946.60 is the total interest income. I can total up the amount of interest income for each year from this spreadsheet, which is from https://treasurydirect.gov/BC/SBCPrice and matches the NFCU receipt to the penny:
| Serial # | Series | Denom | Issue | Next | Final | Issue | Interest |
| Date | Accrual | Maturity | Price |
| NA | EE | $100 | Mar-93 | | Mar-23 | $50.00 | $114.12 |
| NA | EE | $100 | Feb-93 | | Feb-23 | $50.00 | $157.36 |
| NA | EE | $100 | Jan-93 | | Jan-23 | $50.00 | $157.36 |
| NA | EE | $100 | Dec-92 | | Dec-22 | $50.00 | $157.36 |
| NA | EE | $100 | Nov-92 | | Nov-22 | $50.00 | $157.36 |
| NA | EE | $100 | Oct-92 | | Oct-22 | $50.00 | $157.36 |
| NA | EE | $100 | Oct-92 | | Oct-22 | $50.00 | $157.36 |
| NA | EE | $100 | Sep-92 | | Sep-22 | $50.00 | $157.36 |
| NA | EE | $100 | Aug-92 | | Aug-22 | $50.00 | $157.36 |
| NA | EE | $100 | Jul-92 | | Jul-22 | $50.00 | $157.36 |
| NA | EE | $100 | Jun-92 | | Jun-22 | $50.00 | $157.36 |
| NA | EE | $100 | May-92 | | May-22 | $50.00 | $157.36 |
| NA | EE | $100 | Feb-92 | | Feb-22 | $50.00 | $157.36 |
| NA | EE | $100 | Oct-91 | | Oct-21 | $50.00 | $157.36 |
| NA | EE | $100 | Jun-91 | | Jun-21 | $50.00 | $157.36 |
| NA | EE | $100 | Feb-91 | | Feb-21 | $50.00 | $157.36 |
| NA | EE | $100 | Sep-90 | | Sep-20 | $50.00 | $157.36 |
| NA | EE | $100 | May-90 | | May-20 | $50.00 | $157.36 |
| NA | EE | $100 | Dec-89 | | Dec-19 | $50.00 | $157.36 |
| | | | | | | | $2,946.60 |
It is most likely better if you let the IRS calculate any interest and penalties due while remitting the additional tax due with the amended returns.
Note that it can take up to 20 weeks to process amended returns.
See https://www.irs.gov/filing/wheres-my-amended-return
Further, you will have to print and mail the returns for those tax years.
You might also want to consider your other income as reported for at least the 2019 tax year as that tax year is now closed and it appears as if the total unreported interest is $157.36.