Advice on taps (good quality stopcock)

[allondon]

Advice from experienced plumbers will be appreciated. I inherited the old stopcock without a disk (2 pictures below). Attempts to find a lever or disc with 8mm rectangular hole were unsuccessful and use of a locking plier was not convenient in emergency, so another stopcock was fitted after it (last picture). It is of a poor quality and only WD40 allows it to turn after time.
I consider replacing the newer one but don't know what taps are good for a stopcock. Also I wonder if it is possible to find a disc for the old one. Don't want to have a tap that becomes rock solid if not used for a while. Any recommendations?

 

[Deleted member 120897]

I don’t know what you mean by no disc or an 8mm disc, unless you men head? A decent branded stopcock such as Pegler should be ok, or fit a lever ball valve, again a decent brand such as Pegler.