I set out to identify two of the greeblies on the ESB DH17 and a greeblie on the Jabba's Palace blaster. After two weeks of staying up until 3am researching more model kits than I would ever want to shake a stick it... I found them, plus another greeblie that I wasn't even looking for!
I was surprised and delighted that all four come from the same model kit.
Missile on side of the ESB DH17 (Sidewinder)
Greeblie above trigger guard on ESB DH17
Rocket shape on the Jabba's Palace blaster
Greeblie on the side of the Boba Fett ROTJ blaster
And the donor kit is...
Vintage Revel 1/32 scale F-4E Phantom II.
Make sure its this variation as not all the F-4Es have the same weapons racks.
These kits seem to be very rare but the same parts (or very similar) are probably found on other kits. Tamaiya also made a similar kit.