Gretsch (under Fender's supervision) tried bringing out some boutique amps, the Playboy, the Executive and the Variety. These were old traditional names from Gretsch amps and were fantastic amps, made by Victoria, adapting Fender designs. The Playboy was a 15 watt with 1 12" speaker and tremolo. The Executive was based on the Deluxe Reverb and had Reverb and Tremolo, pushing 20 watts into a 15" speaker. I have one of these. The Variety was 40 watts into 3 10" speakers, also with Reverb and Tremolo. These were boutique amps with Boutique prices and were not on the market long in spite of their quality. Now, when they come up they usually will run between $800-1500. Not bad but there was not and still is not a big demand for them. Why? Gretsch was not known for amps. When you think Gretsch, you think of guitars (or drums). The old Valco-produced amps from the '50s-'60s don't create a lot of nostalgia except with hard-core Gretsch fanatics. Guild would probably have a similar or worse response. When you think of Guild, you don't think of amps. Acoustic amps might be another story.
Unless there is something really unique about a Guild amp that would make it stand out when considered with the traditional brands, I think the idea is doomed to failure. A really outstanding solid state amp that was extremely light a la Quilter or the short-lived Fender solid state Bandmaster of a few years ago might be successful. But the traditional tube amp market is so saturated with Fender, Marshall, Vox etc, I just don't see Guild making much of a dent.