Well I bought it for a make believe price, but I'm leaning towards real. John Knibb was Joseph's brother. He worked for Joseph and stayed in Oxford when Joseph moved to London. He made some very fine clocks, but most of his output was more humble to suit his clientele in rural Oxfordshire. It's thought that when his brother returned Joseph may have made posted frame thirty hours for him to sell under his own name. Now here's the thing. Knibb posted frames have a distinctive design. The iron posts are riveted to the top plate but the bottom plate is secured by nuts on the threads on the bottom of the posts. The clock then stands on these threads as feet, a bit like the spikes used by Delaunce and Monk. This movement has that design. The chapter ring reminiscent of a 17th century London clock. The signature in the position of a 17th century clock However those spandrels, what to make of those? They appear in C&W but slightly different. They are rarely seen and hard to date, but no suggestion they are as early as 17th century. The hand is sublime, and I would have bought the clock just for that. you will have to wait a bit for pics as I can't upload them from here, but please look later, it is a puzzle.