I have a 3GS JB with LimeRain 4.1

I want to go to 4.3.3 but snowbreeze is asking what bootrom I have. New or Old. I tried Idetect but it says Unknown device. I tried DFU then looking in USB settings but nothing there looks right.

Did my 4.1 and then Limeraining update my boot?

Model is MC135LL
serial starts 87939

At the end of my rope. Will choosing New/don't know in snowbreeze hurt me?

Thanks

M