sprockets chain gearing question

[Banks]

I recently tore down my 1964 ca78 and found a very worn out primary sprocket 14 tooth. Apparently someone in the past has changed rear sprocket and chain because they arent to bad.
Here are my questions I have aquired a new 15 tooth couldn't find a 14 tooth, will this make it to high geared with a 29 tooth rear. If so what rear size would be recomended with a 15 tooth front.
Also will I have to lengthen chain over the addition of 1 tooth and if so what size is the stock chain.
Any advice opinions or experiance greatly appreciated.

thanks
Mike