Thanks for reaching out about this. There's not currently a way to move content blocks from one mailing to another. I would recommend saving the mailing (with the sponsorship logos) as a template. Then you'd be able to select that template the next time you start a new mailing. This would solve the issue of having to create that multi-image block again. Make sense? The steps for saving your mailing as a template are found here. Please let me know if you have any questions. Happy to help!