I have this same 1/24 3D model and have been wondering how it looks printed out. Thanks so much for printing this and it looks good so far.
Given the choice between the two, I would say Tamiya AS-20 over a black primer. Being a little bit "whiter" of a start I think will work better for weathering and oil washes which will darken it anyway. Plus I prefer Tamiya paints to Testors enamels. I have had issues sometimes with the Testors enamels where they can take days, weeks, or even months to not feel "tacky" to the touch
Although if going with Testors, I might suggest Camouflage Grey instead?
Yes, I have had the same issues with Testors once in a while. Seems like it can go down amazing, or with certain types of plastics or primers (my guess anyway) not so much...
I think AS-20 is probably a good idea and yeah, in looking the Camo Grey does seem like a better match than the Light Gray, thanks for the info! I may snag the Camo and test it out if the stores here have it as I have to way several weeks for the AS-20.