Air Force Unit Patches

Thank you everyone in this sub who has or is currently serving. Looking for where the best place is to find/buy unit patches for my grandpa’s shadow box who passed away earlier this year. He served in the AF from 1954-1977 as a vehicle mechanic, retired as an E-8. I know AF patches aren’t as prevalent as Army units but I’ve been able to find a few of his units but the few I’m missing are:

-823rd Transportation Squadron Homestead AFB, FL (probably going to use 823rd Air Division patch if i can find one) -3245th Air Base Group Hanscom Field Bedford, MA (know it was redesignated as 647th Support Group) -7149th Transportation Squadron Bitburg Air Base Spangdahlem, Germany (probably long shot on this one so going to likely use 49th FW/TFW patch for this or USAFE patch)

Any advice on resources or links to sites would be appreciated. TYIA.