The link I mentioned is to FMA's website. Let's try this link:
www.fmadirect.com

From there, at the top of the page click on "FAQ's" and from that page, click on "Receivers".

Doubling over the antenna is a bad idea, it's better to let it trail behind the plane. Running it up the vertical stab as suggested is usually the best option. I usually poke a hole in the fuse near the RX and run the antenna right out and back to the top of the stab, outside of the fuse.

In theory, you want the antenna as far away from the servo leads and espeically the servos themselves as you can get it.

Also, in theory, you want the antenna perfectly straight, even a 90degree bend is "bad". But in the real world, a bend like that won't matter at all, and may actually help while in the air, when the plane is orientated in different ways. After all, in theory, you want the TX and RX antenna to be parellel but not in line with each other. On some older radios, you could cause a glitch by pointing the TX antenna straight at the airplane, for example.

But the real world is a lot messier than theory, and in the real world, we aren't relying on a "perfect" antenna length or orientation. And as a result, most of the time, if you accidentally shorten an antenna, it's not a big deal. Do a range check to be safe. But if it range checks ok, you should be good to go.