Using a commercial flight simulator - AST ?

Anybody out there successfully interfaced a commercial flight simulator (AST, Frasca, etc.) with FSX or P3D (or Xplane)? I have an opportunity to get an old AST 300 for a reasonable price but I am not sure how it could be interfaced to work with a modern computer and one of these sims. I gather the old versions of these do not have a computer, per se, but have a series of boards that run the various controls, buttons, radios, etc. Only the visuals use a computer according to the person who has the unit.

I know it is possible but it sounds like it would be an incredible amount of work and the dealer actually suggested getting usb sim instruments to replace the ones that are there, and the radios etc. which would kind of obviate the purpose of getting the simulator in the first place.

So ... anybody out there actually done something like this?

Thanks!

Call sign - n4208t