It's an OLD A&M...Take the 6 bolt adapter off...If the end of the crank is smooth with no centering hole the crank is an A&M, not as good as the Sachs crank..If it's a Sachs crank the engine is just as good as a new one, you can't wear out the cylinder and piston....You can lock the timing ring at 28 degrees BTDC and get a syncro module from C&H to use the ignition you have, if it's good....
Many of those old A&M engines were timed way too far BTDC, check it out....