Nice basic cycle brother, good dosages, you aren't overdoing it and are keeping things in check.
Before I Answer the question, I have a criticism though. I suggest you drop the AI And switch it up to 10mg nolva a week, if you feel sensitive on this up to 20mg nolva a week and I promise this is all you will need. You DO NOT need anything stronger than nolva on a cycle like this. I would imagine you are pushing your estro TOO LOW for how high your test is, and an improper balance will HURT your gains, even if its just slightly off! This is very important I HIGHLY suggest doing this! Your AI dose is simply way over done! People on forums are very misinformed and just parrot info they heard... I have over 15 clients ALL on dosages around yours or higher ALL using only nolva. Nolva is about as hard on the body as aspirin.
Now for your cycle length, personally I Would run deca and test for 16 weeks for best results.
I don't pct I am on trt, but I believe it is common to drop the deca two weeks before the test to recovery properly, but again I know VERY LITTLE about PCT so you will have to ask someone else about this.
I strongly suggest running the deca and test BOTH for 14-16 weeks as they take a while to kick in. I think 6 months (24 weeks) is overkill and 20 weeks would be the maximum in my opinion.
You could run it for 6 months but I think your time would better be spent going into cruise or pct and getting into the next cycle sooner!
IMO 12 weeks is too short! I run esters like enanthate (Shorter than deca) for 12 weeks by themselves.