OK From Tensid, Prosoco 766 to clean, then the Limestone afterwash.
They also have Limestone restorer which might be easier for you to use.
Have a good look through Tensid's website to really see what fits with what you need to clean.
One thing though Richy, download any MSDS you need from their website and read them through properly, as some of their chemicals are nasty in the wrong hands. Wear the proper PPE and you will be fine.