Hi mwbsh:
According to Norman Franks book on the Sopwith triplane, he has listed the last S/T being downed on October 12, 1917. Only two claims in September by the Fokker Dr.I's, one by
Kurt Wolff o J11 on the 15th. a Camel and then on the 23,
Werner Voss of J10 claimed a SEA5. This would have both been from the prototypes FI. 102/17 and 103/17. Shortly after this in October the Dr.I's where grounded.
It is most likely that the two planes would not have meet because of the limited number of Dr.I's in action by the time the s/triplanes where withdrawn. I also think that the locations of the placement of the two planes would have made it hard to have seen each other because of the distance.
Mr. Franks may have more information on this.
I hope that helps.
Lloyd...