[TopGunnerz]

Hi everyone, I had some questions about my a&k mk43 I've been wanting to upgrade.

1. Is the cylinder head a v2 or v3 standard
2. Is there an aftermarket nozzle that has better seal? I know there are dedicated aftermarket nozzles but I'm wondering if there are any more common sizes that could work.
3. Is there an online guide on anyone attaching a top rail onto the mk43? Furthermore there is a small ridge on top that would stop me from putting a regular straight bottom rail, so I'm not sure what rail would fit on without some modifying of the rail or the top cover
4. There seems to be a big air leak where the quick detach barrel meets the nozzle, is there any way to remedy this or at least reduce the air leak
5. I've seen 3 ways to fix the hop up problem on the mk43:
i: Replace the sideways nub with a pen reservoir, but I've heard this puts a lot of wear on the bucking and causes it to wear out
ii: Sand the hole enough so that you can fit a regular nub, and then put a spacer or something so that the hop up will engage the nub
iii: Get a classic army saw hop up, I'm not sure if it will allow me to already put a regular nub, or if the hop up works at all and has the same issues as the a&k hop up

Which method works best?

Any help would be appreciated. Thanks!