Haha, I've been away too and am only just back.
Re Siccar Point, I think there are a number of smaller faults associated with the closure of the Iapatus Ocean which caused the folding and uplift of the greywacke sandstone that had formed on the bed of the ocean approx 430 MA . The Old Red Sandstone was deposited some 50 million years later on top of the eroded and deformed greywacke. ie there was a significant gap or unconformity in the geological record. I knew as soon as I saw your photo that it represented an unconformity close by and should have thought of Siccar Point but because I live near the HBF and the surrounding landscape looked vrey like near here, I went for the HBF.
To cool us off in this hot weather here is a photo from the winter. Where is this trig point?