The part number you will need is either PL0252702 (0 MOA) or PLM252702 (20 MOA).
These bases will not fit a Tikka T3X. The model at the link below should work.
https://www.opticsplanet.com/evolution-gun-works-hd-tikka-t3x-tac-a1-picatinny-rail-scope-mount-aluminum-matt.html?_iv_parent-gun-make=tikka&_iv_gun-model=tikka-t3
No, it will not.
You will need high height rings.
Yes, it should.
No, it will not. Here is a link to a model that will:
https://www.opticsplanet.com/evolution-gun-works-hd-savage-round-back-long-action-picatinny-rail-scope-mount.html?_iv_additional-features=long-action
No, these are 0 MOA. The 20 MOA models can be found here:
https://www.opticsplanet.com/talley-picatinny-base-long-action-20-moa.html
You can use model PL0252700 on this page, for the long action model, or model PS0252700 on product page https://www.opticsplanet.com/talley-picatinny-base-short-action.html?_iv_code=9E-T8-PBSA-PS0252700 if you need the short action model.
There are 10 products on the page, I'm not sure which product you are referring to. You can reach Talley at (803) 854-5700 for additional information.
Mark H.
You would need item P00252705 on this page: https://www.opticsplanet.com/talley-picatinny-base.html?_iv_gun-model=weatherby-accumark-magnum-and-mark-v