Camshaft 993cc 3 cylinder

Hi, I have just got a 1996 993cc van. Bought as a non runner owner advised me the camshaft was seizing in the head, on inspection I found that the front rockers and cam lobes are dry of oil, rear two look fine.
Any advice would be appreciated and if the head is buggered what are my options, I know nothing about these engines and would any other hijet engines fit and would it be much of a job to swap
Many thanks......Dave