I have one that was called 'sungold' and it is very similar if memory serves me right. or perhaps its more yellow and 'loose'.

We have Sungold and I have to confess that on seeing some of the others I could not (from memory) tell the difference.

Moonlight (pale) and Golden Glow are the original 1920s cultivars and are easy to tell apart as Moonlight (pale) is cream not yellow. Sungold is from the 1960s and has no lilac at all in the flowers unlike Golden Glow. Honeycomb is just like Sungold but believed to be a slight improvement.
Moonlight Biscuit is, well, biscuity coloured and I have only seen it at the Lavender Garden National Collection; it might be Lady de Ramsey.
The other cultivars with names are either extinct or just synonyms for the 4 or 5 above.

Do you find them tender? We have lost Sungold from the garden twice now It survives as cuttings in the frames, but not in the garden.

Absolutely hardy once established. Try growing one in a 15-25 litre pot (under cover for winter) until it is over a year old and then plant it out. When this size should be tough but the usual advice about avoiding winter water-logging still applies.

Thanks, the said plant was about 4 years old when it succumbed to the weather. Our soil is rather too well drained for some plants. I will keep one of the potted shrubs in reserve.

Mine does have lilac tinges around the edges of the flowers so perhaps not Sungold. Certainly hardy for me but I do keep cuttings every year 'just in case'. I should have pictures in my garden profile section.