Where does Cloth-Head come from?

While I doubt that the term as you hear it is from Jamaican patois, the term clot from cloth is used heavily and pejoratively there. Ras clot (claat) is literally "ass cloth", but figuratively means 'someone contemptible'. Bomba claat is used as well. Blood claat, a used tampon or sanitary pad, is a particularly strong variant.

From The Rastafarian Dictionary:

CLOT: 1. cloth, an essential part of most Jamaican bad words, such as bumbo clot, rass clot, blood clot, etc. The essence of Jamaican cursing seems to be nastiness, rather than the blasphemy or sexuality which is characteristic of the metropolitan countries; to hit or strike - from the verb "to clout"; literally means a used tampon

Glossary of Yorkshirism

Clothead – stupid person

Words in Time and Place: Exploring Language Through the Historical Thesaurus of the Oxford English Dictionary

clot - A middle-class colloquialism for 'fool', but also found widely in dialects of northern England and Scotland in such forms as clothead and cloit, as well as in earlier 'blockhead' expressions as clotpoll (1609). It is often no more than a mild or friendly term of abuse, frequently with a nuance of clumsiness, as in the expression 'clumsy clot!'

Looking at clotpoll/clodpole:

Etymology clod +‎ pole (“head”)

and further clod

Etymology From Middle English clod, a late by-form of clot, from Proto-West Germanic *klott (“mass, ball, clump”). Compare clot and cloud; cognate to Dutch klodde (“rag”) and kloot (“clod”).

Examples

Laughing Boy: The engrossing Yorkshire crime series

"What do you want?" Dave asked, one leg out of the door. "Um, so something fast." "Gazelle?" "No, clothead! Cheese, salad, whatever. Something that's ready made."

Yandro 184

I figure this must be deliberate humor; nobody could be that much of a clothead, so I smiled non-committally.

A Son of Hagar, by Sir Hall Caine

"He's allus stopping short too soon," said Gubblum. "My missis, she said to me last back end, 'Gubblum,' she said, 'dusta mind as it's allus summer when the cuckoo is in the garden?' 'That's what is is,' I said. 'Well,' she said, 'dusta not think it wad allus be summer if the cuckoo could allus be kept here?' 'Maybe so,' I says; 'but easier said nor done.' 'Shaf on you for a clothead!' says she; 'nowt so simple. When you get the cuckoo into the garden, build a wall round and keep it in.' And that's what I did; and I built it middling high, too, but it warn't high enough, for, wad ye think it, one day I saw the cuckoo setting off, and it just skimmed the top of that wall by a bare inch. Now, if I'd no'but put another stone--"