I totally understand how it is just getting back into MTG and having a limited card pool to work with. I figured it was something a long those lines.
I think finding room for 2 Wesvale Abbey is a great plan. As for
Oketra the True, I think you could easily just swap out one of the
Aven Wind Guide for her and maybe just have a second copy in the sideboard for certain match-ups that you need her more. Which if you've been
gone from Magic awhile and looking to get into constructed formats such as Standard, make sure you're thinking of your deck as 75 cards (60 main, 15 sideboard) rather than just one unchanging deck.
Keeping the
Trueheart Duelist is a good idea as you mentioned. I especially like that you can block with her early and then bring her back with embalm for 3 potentially the next turn. Your curve is a little heavy on the four drops so having a turn 3 play after double blocking (and hopefully making good trades) could help.
Speaking of 3 drops, I could see trying to add a few cards here and lowering your number of 4 cost cards. For example
Oketra's Monument is great but you could perhaps run a single copy of it (since it is legendary) and then have several copies of
Trophy Mage to fetch it out of your deck. You could then also include a few other relevant single 3 cost artifacts to up the value such as:
Kefnet's Monument,
Inspiring Statuary (great with all those servos you are making),
Whirlermaker, etc.
I am also wondering if you may be a bit light on land count considering the number of 4 cost cards you are planning to use. Smoothing out your mana curve could help, but you may just want to find room for a couple more lands. Might take some play testing to see what you can get away with, but consistency is important too.