Oil level in shocks.

[cfiddes@direct.ca]

Hi folks.

My '76 Midget is spending a lot of time changing direction after I 
hit a bump.  I figured I'd check on some of the little things first, 
like oil level in the shock absorbers. 

I've got just one, teency, weency little problem.  I have no idea
how to gauge the oil level.  I presume I remove the large screw cap
on the top of the shock and add oil through there, but how much is
enough?

Thanks in advance for your help.

Chris.