Everything is negotiable, but based on the info you've given here you don't have much leverage in any potential negotiation. The only thing you might be able to

Everything is negotiable, but based on the info you've given here you don't have much leverage in any potential negotiation. The only thing you might be able to use is the fact that the acquiring party will likely want your cooperation and possibly to keep you on for a while post acquisition. This is far from completely necessary though so it doesn't give you much. You are not being unreasonable but don't be surprised if your partner doesn't respond positively to your attempts at renegotiation.