Sounds similar to my recipe. I just made some, converting the recipe from the CWA book:
500g sugar
250g butter
Juice 4 lemons and zested rind of three. (I have a zester, so use that)
Cook on 90 for 10 minutes, speed 3 to dissolve sugar.
Reduce heat to 80.
4 egg yolks and 2 of the whites
Beat together first, then slowly pour into
and continue cooking for 10 minutes or so, until it looks like honey. I don't use the butterfly.
It's ready when it coats the back of a metal spoon.
This made 3 jars the size of large Vegemite jars. If you want to keep it in the pantry instead of fridge, use metal topped jars with the button that pops down.
Seal them by putting jars (still with hot mixture) into a pot with enough water to come half way up the jars. Place a cloth in to stop them rattling together.
Bring to the boil and boil for 10 minutes. As they're cooling, the buttons on the jars will pop down, if they don't, they're not sealed and will need refrigerating.