Home wiring types

I've got a home built in 1952 with the vast, vast majority of the wiring being 12-2 plus ground (typical insulation on conductors, what looks like impregnated fabric sheathing). I do have two short runs of black fabric sheathed cable with fabric insulation (?) on the wires (one run from the fuse box to a light receptacle (only thing on the circuit) and one run at the very end of a circuit, running to an outdoor light.)

2 questions;

Are there any resources on the internet that will help me identify the exact types of wire, possibly with photos? (my searches so far haven't found what I'm looking for)
Are there any hazards with the fabric insulated conductors? I plan to replace the run at the end of the circuit but I'd rather not dig into the fuse box if I don't have to.

Thanks in advance

Don't know of any. These are probably just classes of NM or SE cable from various points in time.

The cloth outer covering isn't typically a problem. If the individual wires are cloth and not plastic insulated, these can get brittle over time and the isulation just crumbles away. This is compunded by overly hot light fixtures (i.e. 100W lamps put in where a 60W was all it was rated for). If you don't touch it, it tends to stay in place. But if you work it, and it crumbles, it definitely needs to be replaced. You can give some protection to this circuit by putting old wires on an arc fault breaker. But it is better if the arc fault never has to do its job and you fix the fundamental problem first.

-- Mark Kent, WA