This right here. The money OP invested -- whether hard cash, or equivalent deferred pay or both -- should have resulted in direct, fully vested stock, just as it does for angels and VC's. (to clarify: it should vest at the rate that the work is performed, not over some arbitrary schedule).
There's this underlying meme in our community that "elbow grease" investment -- working for low pay, no benefits, rejecting other career opportunities -- is somehow worth less than an investor's cash. IMSHO, it's just the opposite -- cash typically doesn't draw down one's pool of emotional well-being and spirit the way hard work does. Work investment should be rewarded with a premium, not treated as somehow less than just money.