my '87 300e was tex interior. I understand that prior to '89 or '90, tex was standard with leather optional. I am uncertain as to when the 300E's began carrying leather as std. If you have read that '89's had leather std, I wonder when during the year yours was built...could it be a late '88 manufactured '89 ???
Look at the bright side, MB Tex is virtually indestructible...Mine mad it through infant seats and 225,000 miles of use...