I know a girl here that will do a head job, around $20.00, that the kinda of head you talking about.
Timing chain is easy to change, you do not have to take engine apart.
Service manuals, you are a dreamer aren't you?????
No such thing, that is unless you have a 25th car, and that ain't much.
If you get the car and need parts, I stock Countach parts and have been for over 25 years.
You can email my address is: JaguarXJ_S@Yahoo.com
That is the best way to contact me anyway.
Chadbourn Bolles
803 798 3044