You could try a plugin that does it all in one:
http://www.digieffects.com/product/damage
A tutorial on how(edit: removed video example for aged film - was intended to useshow the Aged Filmpowers but could mislead to think it only produced aged film look).
With the plugin you should be able to produce the old video tape look using one or more of these in combination:
Go directly to features (thanks Inan):http://www.digieffects.com/product/damage#features
Artifact: Create displaced pixel blocks, color errors, frame dropping and video compression artifacts
Blockade: Control color inaccuracy, block size, speed, and temporal frame stuttering
Destabilize: Create convincing camera shake or earthquake simulations
Interference: Simulate the CRT look of a security camera or interlaced video
Overexpose: Overexposes images just like your eyes would
Skew: Create analog noise with reckless abandon