topping up sparkling wine
 

Hello, everyone -

I am making a white from a kit which I plan to sparkle by fermenting it
still then bottling with a sugar solution (same as doing a beer). My problem
is that the level is a bit low in the carboy. I don't want to add water and
I don't have any marbles. But I do have 30 bottles of a similar white wine
sitting around. Could I use 1-2 of these to top of my to-be-sparkled wine? I
finished them off with sorbate and metabisulpite when I finished the kit a
couple of months ago. Will the amount of these chemicals in 1-2 bottles be
enough to interfere with the sparkling process when I bottle this new kit?

Thanks, as always,

Gabriel