You bought it now its yours. should have been like me and not looked and wondered for half a year before you checked. you say it runs fine, so that means it is fine. use premium fuel, synthetic oil and drive hard. if you want to worry more than worry about getting a leakdown test, I did a comp test on mine and thats as far as I wanted to go with testing. mine runs great and I dont lose any sleep over it at all, dont forget about the Alusil people that dont know what their missing...
ahhh I love the smell of Nikasil in the morning!