нашел тут на одном форуме прошивку вами названную. 1.7
в описании
"Latest update from the great NeurOn. if your already on 6.60ME, just place the "UPDATE" folder from this download into your "GAME" folder on your memory stick and run it from your PSP. An alternative method is to just use the "System Update" in your "XMB" and update via NeurOn's server. Word of caution, this is only for 1000 and fully hackable 2000 PSP's. If you have a TA-088v3 Slim, 3000 or a PSP Go!, DO NOT USE THIS!!!. Instead use the LME version. "
то самое? не верю что так легко стало прошиться...