Timing cover

I need some help deciding which cover to use, it's going on a 401 with a solid roller cam, using a machine bolt as the anti walk stop , and will be running a Romac balancer .The first one is a stock 68 cover that ran good in my 68 had good oil , the second one is a 69 one that i got with a motor i never use , and the third is off a late model 360 , the timing marks are different . I notice the first one looks like the cam bolt ate a little  , would this hurt my anti cam walk button ?.Thanks,second, third  

I was thinking the third , but were the timing marks are different i didn't know if they would line up still, and another question is how much play do i want on the cam button , i heard .010 is what you want , the motor i have been set up once for already but i want to check the play when i get to that point, would it be best to make a new button with like a plastic cap on the end of it or just leave the machine bolt i got in it . or buy the cam retainer kit they sale .Thanks

Thanks, whats the best way to check that , plastic gauge , or a indicator on the cam lobe threw the valley and move the cam . 

Just wanted to make sure you knew when I said timing chain and cover you know I meant as it would be on final assembly to include cover gasket, fuel pump eccentric, distributor gear, the entire assembly for accuracy on end play.