[renewiltord]

All example 83-b have this problem. Since there is no form and it's just a letter, you can just add the line and do it yourself. IANAL.

[jiveturkey]

Clerky's 83(b) does not have this problem.

[swampthing]

Correct! We've always included spousal signatures on 83(b) elections. I would say the vast majority (if not all) forms I've seen from good law firms have explicit places for the spouse to sign.