I bought a second hand car ('93 Miata NA, 40k miles) and am swapping out the old rubber coolant hoses.

The inside of the hoses and the radiator are full of this beige gunk.

Should I be concerned about this/how can I fix it? Is this indicative of any other problems i should check out?

The gunk comes off really easy with a tissue, its not hard or anything, but its everywhere. The radiator is almost full of the stuff!