StdRef_1.18.0.pdf StdRef_1.19.0.pdf from the web site are not PDF/A
Replace with the ones in this dir, which I ingested earlier.
All 1.20 and 1.21 pdfs were PDF/3A. Ron punted and sent me the .docx.

https://xodo.com/pdf-to-pdfa worked. once/15hour limit. Even got DPH1.20 to work
https://avepdf.com/convert-to-pdfa worked.  MADE BAD -1A for PDS4_DPH_1.20.0_final_20230605.pdf
https://www.ilovepdf.com/convert-pdf-to-pdfa works. Limit of 1?
https://www.pdf2go.com/convert-to-pdfa converted but with mistakes that failed validate
https://tools.pdf24.org/en/pdf-to-pdfa 2b only
https://products.aspose.app/pdf/conversion/pdf-to-pdfa1a failed on StdRef_1.21.0.pdf
https://pdftoconverter.com/pdf-to-pdfa/ produced bad PDF/A-1a
https://deftpdf.com/pdf-to-pdfa only PDF/A-1b