頭高型 is a technical term which is also a compound noun. Ordinary native Japanese speakers usually have no idea about what 頭高型 means, so it's not surprising to me if it is not listed in an accent dictionary.
Anyway, according to online videos (1, 2), the pitch accent of 頭高型 is あたまだかがた【LHHHHHH】. I think you can infer this if you know the pitch accent of 頭 and ～...
You mention acronyms but give examples of abbreviations in names. My answer assumes you mean abbreviations.
It's standard to use romaji for the initials in people's names (abbreviations). For example,
OJ Simpson = O・J・シンプソン
T.S Eliot = T・S・エリオット
George W Bush = ジョージ・W・ブッシュ
As for acronyms, it seems to be a mixture. Well-known acronyms can be used in ...