Did you search for "gladstone bag pattern"? I did and came up with three. I found that most of the makers called them U bags. There are lots of PDF files with bag patterns in that search; some free, some for sale. You would have a pretty small bag if it were an embroidery design. I cannot help you there, but maybe one of our genius digitizers can.... Good luck.

If you are looking for designs, try embroidery library or emdbroidery design sites. lots of designs there

I know of no free one but someone might.
In meantime www.embroiderydesigns.com has some
If the link below doesn't work just copy and paste the URL and search at the site doctor bag and a few pop up.