Here’s a web site with scans of a booklet published by General Motors, that includes some details of how Shermans were prepared for shipping overseas:
https://usautoindustryworldwartwo.co...orsservice.htm
And a model I built a few years ago to show how a Sherman would have been waterproofed:
https://www.tapatalk.com/groups/miss...9888&p=1656069
The M10s would have had much the same work done, except instead of taping up the turret they seem to have had a big box structure built over the open turret.