This part is likely more for ceremonial use than active duty but given the wear it is possible it was used for both

it is a very dark navy blue

known for its use during the Iraq war

While rank cannot be told from this exact pair of trousers

Modern British surplus still being issued today

US Air Force Nam Era Tactical Air Command Short Sleeve Shirt Mimetico Roma 90 This part is likely moreAt a glance Cotton & Sateen Blend Material 2 Button Chest Pockets "U. S. AIR FORCE" Patch "HOLZER" Name Patch "TAC" "Tactical Air Command" Patch Technical Sergeant Rank Sleeve Patches Durable & Hard Wearing Vietnam War Era Solid Olive Green Colour Chest Size: 51" X Large Regular Collar to Hem 31" Vintage Militaria Dated 1967 Genuine US Armed Forces United States Army Surplus Grades Grade 1 Great condition, has general signs of use. A small marking