Cassette Cogs - Alignment Help Please

[cosmicbike]

I'm in the process of putting a new cassette together for my Dads bike. It's fitted with a 6 speed Uniglide cassette, and I've found NOS 7 speed cassette. A few questions if anyone can help..

1. Can I simply fit the 7 speed in place of the 6?
2. If not, how should all the gear teeth align down the block? I've struggled to find anything on this, it's not an issue with Hyperglide, but the older Uniglide allows a multitude of different positions per cog...

Ta

 

[Mobytek]

source of knowledge http://cycleseven.org/uniglide-and-hyperglide-compatibility

 

[andrew_s]

It doesn't matter which way Uniglide cogs go onto the freehub body.
It does matter for Hyperglide cogs, which is why Shimano introduced the wide spine, to force you to put them on in the right way.