[Roadsters] hub cap clips

[Tim]

While finishing the scrapping of one of my part cars (the rusty basket case not able to be restored), I noticed that three of the stock wheels had partially or wholly broken off hub cap tabs. 

Does any one know how much of the tab has to be there to hold the hubcap? 

If part is broken off and the hubcap will not stay on the wheel, are the stock wheels worth saving? (I have another three+ sets between the two running Roadster and the other part car so I am not low on stock steelies.)

TIA 

Tim
Dairyland Datsuns