None of the answers given so far seems satisfactory to me. As none of the answers shows a date of compilation of the copy presented as the original.
An original manuscript of Sahih al-Bukhari in Andalussi or Maghrebi script is impossible
First of all the one must be aware that the copy presented in the accepted answer was showing copies written in a Moroccan (Maghrebi)-Andalusian script which only was used (or became a standard) in the end of the 4th hijri century (earlier the scripts of al-Anadalus and the Maghreb developed independently according historians such as ibn Khaldun -See also in Wikipedia in English and Arabic-) and developed in al-Andalus and al-Maghreb. While imam al-Bukhari completed his book around 232 a.H. and died 256 a.H.). Further according to this Article Sahih al-Bukhari didn't reach al-Andalus and what is now known as Morocco before the 2nd half of the fourth century (as the scholar 'Abdullah al-Asylee (al-Aseeli) عبد الله بن إبراهيم الأصيلي whom transmitted it only went out seeking knowledge around 351 a.H. and he heard it from al-Marwazi -will be introduced later- in Mekka). Whether it reached other Maghreb states much earlier should be checked and investigated.
Moreover one can safely say that imam al-Bukhari didn't know the Andalussi or Maghrebi script so an original copy using this script is impossible. But copies of students of his students in this script might more likely be possible.
Further in the link of the accepted answer (The King Abdul Aziz Public Library in Riyadh, Saudi Arabia), the oldest manuscript was dated back to the 10th hijri century which is around 700 years after al-Bukhari.
See also islamqa fatwa #193912 on original scripts of the two Sahihs.
The earliest -existing- manuscripts of copies or parts of Sahih al-Bukhari are dated back to the 4th hijiri century
Secondly all the given answers neglect the fact that nobody claimed to have found the original manuscript of al-Bukhari. In fact the earliest existing manuscript -incomplete- refers to dated to 370 a.H. hand written by or from the narration of abu Zayd al-Marwazi أبو زيد المروزي a shafi'i fiqh scholar -born 301 a.H. and died 371 a.H., see also in Siyar a'alaam an-Nubalaa' سير أعلام النبلاء here in Arabic - and student (narrator) of al-Bukhari's student of Muhammad ibn Yusuf al-Farbari محمد بن يوسف الفربري one of the known transmitters of Sahih al-Bukhari who died 320 a.H. who heard it from al-Bukhari according to imam a-Dhahabi -in his Siyar a'alaam an-Nubalaa' سير أعلام النبلاء -see here in Arabic- twice in Farbar فربر (Farap) in the years 248 a.H. and 252 a.H.. In his biography in Siyar a'alaam an-Nubalaa' abu Zayd al-Marwazi said about when he heard Sahih al-Bukhari from al-Farbari:
In the following I'm translating from Arabic language, as these translations are of my own take them carefully!
سئل أبو زيد : متى لقيت الفربري ؟ قال : سنة ثماني عشرة وثلاثمائة .
Abu Zaid was asked: When did you meet Al-Farbari? He said: In the year three hundred an eighteen.
Thirdly beside the -Arabic- wikipedia article on Sahih al-Bukhari listing some known copies of old manuscripts:
- أقدم نسخة معروفة حتى الآن التي نشرها المستشرق منجانا في كمبردج عام 1936 م، وقد كتبت عام 370 هـ، برواية المروزي عن الفربري.
The oldest known copy so far was published by the Orientalist Manjana in Cambridge in 1936 AD, and it was written in the year 370 AH, on Al-Marwazi's narration on Al-Farbari. (See also in the English wikipedia article)
- نُسخة الإمام شرف الدين اليونيني الحنبلي.
The copy of the imam Sharaf al-Din al-Yuniny al-Hanbali (Examples of this manuscript can be found here).
- نسخة الحافظ أبي علي الصدفي (ت 514 هـ)
Copy of Hafiz Abi Ali Al-Sadafi (d. 514 A.H.)
- نسخة الحافظ ابن سعادة الأندلسي (ت 566 هـ).
The copy of Al-Hafiz Ibn Saada Al-Andalusi (d. 566 AH).
- نسخة عبد الله بن سالم البصري، المكي (1050 هـ-1134 هـ)
Copy of Abdullah bin Salem Al-Basri, Makkah (1050 AH-1134 AH)
You may find further information about these books in the fatwa form islamqa linked above like:
There is also the copy of the imam and hafiz Sharaf ad-Deen ‘Ali ibn Ahmad al-Yoonayni, who is known as al-Ba‘li al-Hanbali (d. 701 AH). He checked it against the original copy that was read to al-Haafiz Abu Dharr al-Harawi, and the original copy that was read to al-Aseeli, and the original copy al-Haafiz Ibn ‘Asaakir, and the original copy that was read to Abu’l-Waqt in the presence of the grammarian and linguist Ibn Maalik, the author of al-Alfiyyah (d. 672 AH).
A book on the manuscripts
Further there's a nice book about some manuscripts of the book called Kitab Riwayyat wa Nussakh al-Jami' as-Sahih (The narrations and manuscripts of al-Jami' as-Sahih) كتاب روايات ونسخ الجامع الصحيح of Muhammed ibn 'Abdalkarim ibn 'Ubayd محمد بن عبد الكريم بن عبيد -a contemporary scholar/researcher- which none of the former answers apparently consulted.
Edit & Note
All wikipedia link are permalinks, please let me know if the articles have been updated, so that I can check if something useful can be added (updated).