You talking base to bottom of ring .250"? Like how Burris measures theirs? Not really sure of anyone that is lower than that. What are you putting it on that needs such a low ring?
The Seekins "low" 30mm rings would be right around 0.23" from the base of the ring to the bottom of the scope tube. If you take the Seekins measurement of 0.82" from ring base to centerline of the scope tube, subtract 0.59" (1.18" is 30mm, so 0.59" is 1/2 that amount) you get 0.23" from base of the ring to base of the scope.