Vintage Renwick brown briefcase leather bag

Gently used and shows some wear due to age and use. No tag with fabric content but I used leather conditioner and the material just soaked it up so pretty sure it’s leather. Has a long shoulder strap too. Strap drop is 18 inches approx. depth 2.5 inches, height 9 inches up to zipper but total height around 10.5 inches (due to the leather that goes above where the zipper is, length appx 15 inches