Hi Steve,
Have you been able to discuss this with the original author? Perhaps if you can reach an agreed view, an author’s amendment to the paper might be appropriate and acceptable to the editor, avoiding the risk a protracted discussion. Although not strictly peer review, ArXiv can indeed be rather good in this respect where the on line version can reference the conventionally published version and be subsequently revised with the original version still accessible. (and useful for us poor amateurs unable to access papers behind paywalls of course!) It still would not allow easy tracking back from the Journal version though unless pre published on arXiv and referenced in the Journal version. I see some journals actively encourage authors to mirror their papers on arXiv. I am not sure what JBAA view would be on this however.
Cheers
Robin