Objective doublet assembly

Hi there , ihave recently aquired a celestron firstscope 80 refractor , the objective lens although in good condition was very dirty ( the result of being kept in dusty shed with no dust covers ) having removed and cleaned objectives i have noticed that the front lens of the doublet seems to be more convex on one side compared to the other, and as a result or my stupidity and not noticing i am unsure whitch side should fit to the second element ( i.e. more convex side facing second element or facing away ) i would realy appreciate any advice u may have as i currently have a dead scope ....thank ? s alot hope u can help......