That’s a nice little collection, especially the RAF sweetheart pin.
The brass badge looks to be a decorative piece of fantasy heraldry with no particular significance apart from the Maltese cross.
It helps us all if you say what you already know (about the others), but what I see… taking them in order from the top left of the first row:
- US 101st (Expeditionary) Signal Battalion, but it’s a sweetheart badge. It’s the wrong colour for a military DUI, but sweetheart badges were produced in a variety of non-regulation colours.
- Black metal USMC garrison cap badge, also worn on WWII combat caps.
- Royal Scots Greys (2nd Dragoons) cap badge. They were known under that name from 1877 to 1971 when they were merged into the Royal Scots Dragoon Guards, but the badge looks to be WWII or post-war.
- US Navy Officer’s hat badge.
- British (& Empire) Victoria Cross, introduced in 1856, but a replica. Only 1,355 medals have been awarded since inception and a genuine example would be worth up to several hundred thousand. On the reverse, the suspension bar would have the recipient’s details and the centre of the cross would have the date it was awarded.
- US military Marksmanship badge awarded for “Expert” level achievement. The “Grenade” qualification was first added to the list in 1928.
- Badge for the Sun Valley Ski Club, founded in 1936 in Sun Valley Idaho and still in existence using the same logo.
Not sure on the others or the rank insignia but the pin with US Air force emblem would date from 1946 onwards and the pin for 1,000 hours service in B-47 Stratojet would date from 1951 to 1977 at the latest. Replicas exist.
