I was going to say if the manual says there are timing marks, then there are timing marks - but after you said Haynes & Mitchell - I decided to hold my tongue on that one.
There ARE timing marks though, you just need to know where to find them - look at the front cover just above the crank pulley, you should find a single ridge, vertically aligned with the crank bolt - that's the fixed mark.
Next look at the edge of the crank pulley - from memory it's the leading edge of the inner pulley - you're looking for a single notch, it's easier to find it by feeling for it - rub the edge of a knife or flat blade screwdriver along the pulley and you'll find it - put a dab of white paint on it, when you do - that will make it stand out with the timing light.
Also you can use an inductive timing light with coil-on-plug - I don't guarantee any inductive timing light will work, but I do know that the Equus 5568 does - additionally your 96 will have "two wire" coil packs (the later models have "three wire"), which I have not tested with - still there's no reason it should not work, you'll need to separate the two wires and clip the pickup over a single wire. Since there is no "scale" showing the amount of advance, a gun with an electronic advance (like the 5568) is required.
Two more things - if you're looking at the ignition timing with an OBD2 reader you will not see a change when you rotate the cam position sensor - the electronics are displaying the so to speak "electronic advance" and using the cam position sensor as a reference - you are adjusting the physical or mechanical advance - a timing light will show the change because it has a physical reference, and is displaying both the physical & electronic.
Finally the bad news - you could have simply left the timing where it was, as long as you had left the cam position sensor undisturbed during the chain replacement - all you would have needed to do was ensure the cam timing was correct, and the igntion timing would also have been correct (or at least where it was before you started).