yes, the 5% jumps right out at me. It could be possible this is an old 30-year bond that was issued with 5% coupons that was stripped a long time ago. BUT, two problems besides the fact that STRIPS don't pay interest and come with an interest rate, so the original rate is irrelevant. First, it still would only yield the current market rate for 5 year maturities, which today is 1.50%, give or take. Second, these bonds can only be sold and held by financial institutions and government bond dealers. No way could they sell a bond over the market rate - regulators would be all over them.
This bond my not be as obviously bogus as a Morgenthau Bond, but it still make be fake.