Looking for a couple of the pre 1981 valve retainers (single spring)

[turbodave]

I had a single spare, that I've misplaced, and have one damaged from a pair of heads (spring broke, causing interesting damage).

The retainers I want are the single-spring units from the (I believe) 1976 on heads - most likely TR8 / SD1.

Clearly visible as machined - compared to the smooth finish of the sintered later units (see attached).

If anyone has a whole heads-worth, I'm also interested in another complete set for my spare heads.

[turbodave]

I didn't make that very obvious.... The ones I want are like the pic above with the machined faced. Smooth face are sintered.