1976 was a transitional year for Fender with the serial numbers being moved so they are a bit more collectable, arguably. The pickguard being non original is going affect his price though. I bought a 1978 with original receipt, strings, no mods & that was £1500. Some of the mid 70s stuff is now £2000 BUT it depends on condition, history & being original. You really need to post some pictures but I guess without the original pickguard you'd be looking at no more than £1500 at the top end and £1200 as a starting price if the paintwork is originally & it doesn't need or has had a refret