I have recently undertaken a complete stripdown renovation of a TX200 SR.
I have pretty much stripped it to every individual part, I have sent all external parts off for a traditional rust blueing and have been busily cleaning, deburing and polishing the life out of everything else. I have bought all perishables - o rings, piston seal, delrin washers, m5 aero tight nuts etc. Ready for when I reassemble.

I have absolutely no concerns about reassembly, as the TX is a breeze to work on. My question is relating to loctite. I have never applied it to anything I have worked on, I have had experience undoing it the past though.
So, where would you recommend the key areas are? I know the barrel retention nut definitely had some, but I'm not sure if the barrel itself needs it as it is located?
Which loctite should I use, I didn't realise there were so many.

I know it probably sounds like I'm a novice tinkerer, but I'm really not - I've just always relied on regular maintenance to keep loose nuts at bay.

Thanks in advance for your opinions.