Track Control Arm

[barryjdart]

HELP. I have an mot advisory for the nearside front lower balljoint and would like to replace it, I believe it is the track control arm. Have done a search and there are two different types - 16mm and 20mm cone fitting, dependent upon Vin/Reg. no. Ill health prevents me from looking for part nos. and I get mixed feedback when contacting suppliers, some say 16mm others 20mm. Anyway can anyone help?

Reg. no. CP55 PYD
Vin. no. wwwzzz3Bz5E159547

Thanks