First, here's a
short timeline of GSEClarktor Tug at Unknown Museum
Source:
Aircraft Tugs - G503.comHarlan Tug with Baggage Trailer at Syracuse Hancock International Airport

Source:
MUSEUM MONDAY: DISCOVER THE AIRPORT! EXHIBIT AT SYRACUSE AIRPORTUnknown Tug at the Classic Rotors Museum

Source:
Full Time Photo Gallery - Jan 2006493rd Bomb Group MuseumBentwaters Cold War Museum- 1986 Jeep CJ-10A Aircraft Tug - Marked as "85C 504", Restoration Thread
- 1960s MB-4 American Coleman Aircraft Tug - Donated by the Vulcan Restoration Trust
- 1964 International Harvester Bus - From RAF Upper Heyford, former USAFE
Estrella seems to have updated their website, and as a result have listed 3 more tugs on it. One was
noted previously in this thread with its own page on their website and is not included below. Another of the tugs listed below (marked as #3) was also
pictured in this thread previously, but without its own page. Finally, a third tug (marked as #2) pictured with the latter is does not currently have a page on their website. In sum, it appears that the EWM has, or had, at least 5 tugs.
Cheating on the narrow specificity of this thread a bit, here are a few in non-aviation military museums:
Federal F-55-AF 1954 at the "ArmyCars Museum" - museum has since been
reported as being closed, with the
entire collection claimed to be moved to the Overloon War Museum
Aircraft Tug at the General Patton Memorial Museum