Between eBay and Rock Auto all the parts can be sourced to rebuild your X350. The only arms that do not appear to be the same as a Lincoln LS/Ford Thunderbird are the front lower.
The curved arms look recent on mine, ordered the outer and inner rear bushings for these front lower control arms.
Found a Ford dealer on eBay that had good prices for Ford parts. Delray motors. They have the front upper arms for about 140.00 each. The rear toe adjusters for 111.00 each. The lower LH arm for 219.00.
The lower rear LH arm arrived with Jaguar ground off. They left the SC on it.
Sourced the RH lower and rear uppers from Rock Auto. The upper are 120.00 and the lower right 278.00.
There is a mistake in the rear arm listing. They call the rear lowers rear uppers. The Lemforder part number is 3063801. This is a rear lower right side. The listing shows rear upper right side. The picture is a lower arm also.
Ordered TRW tie rods ends for the front.
The rubber was in bad shape on my car. Hopefully it will ride like new now.

 

Thanks very much for the write up. Note that Jaguar lists different rear lower control arm part numbers about half way through the x350 model run (2004-2007)

 

The rear arms are the same as Ford/Lincoln. The front upper are also. The lower front are different.
Hopefully when they changed to part number for the arms they upgraded the rubber used. But this may be the X350 - X358 changeover. The X350 is all I have looked at.

 

The arms arrived today. The 120.00 Front uppers as speced. The right rear lower is listed at Rock Auto as a right rear upper. The arms are OEM, has Jaguar ground off and the SC on it.
The Powerflex Bushings from the UK are 300.00 plus shipping to redo rear lowers. These may be better, but I am going back stock.

 

I did the same thing and documented it with plenty of pics a few weeks ago. Look in my car diary, and the "upper rears" thread on the first page of this section. We also discussed it in another recent thread, on the same page.

It is good to know they work for sure. Mine were stamped Jaguar.