Looking at both new and used 21FSB TT's. The 2009 came with half time oven which is not longer used by North Trail..I think. Looks like lots of problems with half time...my question, if I bused the 2009 with half time oven and it stops working.....can it be replaced..easily..with different brand. In other words...is the space standard...and just drop in new unit. I assume the oven and stove part are one unit? Just want to see what my options would be.