jonburdon1 I did add an instagram using that option in the template, but the styling didn't apply. I make a few small changes to your css, hoping they would also apply to the instagram icon - but the changes didn't work.
Try change the above CSS :
.social-wrap .zen-icon-facebook, .social-wrap .fa-facebook,.social-wrap .zen-icon-twitter, .social-wrap .fa-twitter{background:#000 !important;border-radius: 50%;}
.social-wrap .zen-icon-twitter:before, .social-wrap .zen-icon-facebook-f:before,.social-wrap .zen-icon-facebook:before{color:#f0a02f !important;}
to
.social-wrap .zen-icon-facebook, .social-wrap .fa-facebook,.social-wrap .zen-icon-twitter, .social-wrap .fa-twitter,.social-wrap .zen-icon-instagram, .social-wrap .fa-instagram{background:#000 !important;border-radius: 50%;}
.social-wrap .zen-icon-twitter:before, .social-wrap .zen-icon-facebook-f:before,.social-wrap .zen-icon-facebook:before,.social-wrap .zen-icon-instagram:before{color:#f0a02f !important;}
which would ensure Instagram FA icon inherits similar style