Just found some pretty good shape black veneer Signature Q/5 bookshelf examples with new correct foam surrounds and open cell foam in the resistive port, and I'm very, very impressed.
Super solid, tight box. Well-constructed drivers. The grills are a weak link IMO, both style and construction, but oh well.
They sound fantastic. A whole heaping helping of solid, fast bass from a teeny tiny enclosure. Not much info out there on this specific example, though...