Tim - similar issues to yourself awaiting new high level PC capable of running P3DV5 or MSFS2020 (future proofing I think of it as my older machine just cannot be upgraded due to motherboard limitations).

I would concur with MarkOZ's view. I will reinstall FSXA onto the new machine and then install P3DV5. I am not interested in MSFS2020 and LM are well ahead of MS on the 64 bit architecture issue.

You will not be able to portover a lot of FSX stuff into P3D and virtually none into MSFS2020. But a lot of FSX stuff works just fine in P3D if it is a genuine FSX native aircraft it will go over but the guages and textures may be an issue due to the coding not working in a 64 bit environment and the texture mapping or type that is all. There a lot of folk out there working on fixes and updating for P3DV5 but everyone is sitting on the sidelines with MS2020 due to the useless SDK and changes to the sim core engine and the sheer amount of redesign and rebuilding work required to do it. I wouldn't either. I am doing some work with a couple of people do upgrade some earlier FSX stuff so it runs properly in P3DV5, mainly changing coding for gauges. The texture rework will have to come later.

As for Captain Sim well the 707 and 727 are the reasons I am reinstalling FSX but in time something will arrive for us dedicated Capt Sim folk to use in P3DV5.

I spend most of my time now preparing my box of bits of addons of aircraft, scenery etc for transfer into the P3DV5 world. Time well spent in my view.