Replacing LP12 arm with Well Tempered Simplex Arm

Call Jonnie at Audio Origami. He builds his PU7 tonearm to Linn spec and you can order as many upgrades as you want. His arm is superior to either the Ittok or Ekos. Jonnie is the premier authority on
Linn arms and the better replacement options.

IMO, the Ittok or Ekos are a significant upgrade over the Basik and will drop in with no problems.  I can't imagine why someone would want to perform surgery on an old table when the available products work so well with the table. But that's me. 

I run a custom WTA ‘Black’ arm on my LP12 Radikal D...sounds great! It is no easy task to set up, but once set up it stays that way. The benefit about the WTA is the very light weight which works well with the Linn suspension. Look at my profile to see pics of the table and arm

In my experience 2nd hand tonearms can be problematic, you never know whether they have been mistreated, and are in good order.

I would suggest you get your Linn serviced, and see if you can afford either the Ekos or new Krane arm made for Linn by Clearaudio. Avoid the Project arms - they are junk.

Budget killer in my experience for a non Linn arm would be the Audiomods 6 tonearm. Easy to set up, VTA on the fly and great performance for the money.

I set one up on my old Platine Verdier when I sold it and it held its own against my regular Dynavector, Naim Aro and FR64s tonearms on the same deck.

I have set up Well Tempered arms on the Linn, its ok, but fiddly to set up and I dont think the performance on a Linn is very good for that arm.

The arm is A Linn Basik2 +an Ortofon MM

What tonearm & cartridge is currently fitted to your  Linn.