Frame builder is Kevin Winter from the north east. The penguin logo is something of a trademark of his I've seen on a lot of his frames. Not sure if he's still building frames these days but seems to have a good reputation.
Crown race looks ok to me. It's the top lock nut part that doesn't look right. The top lock nut should be sitting pretty much flush with the top bearing race cup assuming that the steerer has that notch in it to take the lock washer that fits between the two.
The metal cups have a plastic cover...
I've taken a screenshot of a frameset a seller has had for sale and marked on the screenshot where to measure. Trying to explain to some folk who don't know much about bikes about what measurements you want can be hard work.
I'd agree with this. Ultegra 9 speed with Shimano 600 threaded headset and seat post and the Mavic ceramic rim wheels which you don't often see in such good condition is worth it.
I recently sold a Cadex CFR frameset on Ebay for £40 so the frame on its own isn't worth that much so probably the...
I see Malcolm has closed The Cycle Clinic for good due to the "challenging trading environment". He built some lovely wheels for me a few years back and seemed to be doing ok in the wheel building trade but obviously not good enough.
https://www.sjscycles.co.uk/brakes/shimano-ultegra-br6800-cable-fixing-bolt-plate-frontrear-y8la98020/
This what you're looking for? SJS carry a lot of Shimano brake spares so might be worth a look there for what you need.
gios.it is the website for the ones made in the far east, giostorino.it is the website for the original Gios company building custom frames still in Turin.
This previous thread might be of some use if you're trying to fit down tube shifters to a Cannondale.
https://www.retrobike.co.uk/threads/shimano-ultegra-600-downtube-shifter-issue.474117/