Thanks konazxiii - that approach makes sense.
Just to close the thread, the data was a high priority so I looked at 3 pros:
https://drivesaversdatarecovery.com/ , https://www.stellarinfo.com/ and https://www.ontrack.com/
All came recommended (especially the first) and all seemed reputable. Price was also a factor, and the latter came in with the lowest quote range so I went with them. Their communication was a little patchy at times, but they got the job done as promised (I received an encrypted external USB drive with the needed data) and within my budget.