Working on phased matroids (a generalization of oriented matroid to the complex case) I've found an interesting formula for computing the inner Tutte group (and, hence, all the Tutte groups) associated to a matroid $M$ with a ground set $\sharp(E)\leq7,$ without minors of Fano or dual-Fano type.
I also wrote a sage programme which explitly compute this group. I've already do the computetion for the matroids:
$F_{7}^{-},$ $O7,$ $P6,$ $P7,$ $Q6$ $R6.$
In fact, these are all the matroids with $\sharp(E)\leq7$ I've found in the sage library. My question is the following:
Are there some other interesting matroids $M$ with the condition $\sharp(E)\leq7$ (without minors of Fano or dual-Fano type)?
Maybe this matroids arise from some interesting geometric or topological construction. Could you please explain where these matroids come from?