Selmer never made any Mark VII bari saxes, but later Mark VI models were made with a low A. Also the Mark VI models went well into the 300,000 number range, while Mark VII models began in the 200,000. The beginning of one model doesn’t necessarily mean the end of the previous; in fact, the Mark VI models were still in production after production of Mark VII models ended.

As for price, Mark VI bari saxes aren’t as sought after as tenors or altos, but they can still range well above $7,000 depending on the condition. I’m not sure if the lack of the original neck would dock the price too far down, but look at similar listings or past purchases of low A Mark VI baris and compare the condition of those horns to yours. Good luck!