Tailwheel pilot reported loss of aircraft control occurred during landing rollout with a tailwind when a gust of wind pushed the aircraft. The pilot applied rudder inputs and braking; causing the tailwheel to malfunction; resulting in a runway excursion.

Narrative

I conducted a ferry flight for a recently-purchased aircraft from ZZZ to ZZZ1. I performed 1x high speed taxi and 2x full-stop landings before departing. Then upon arrival at ZZZ1; I conducted 2x planned low approaches and then conducted 1x full-stop landing. Winds were a right quartering tailwind on landing (300/10G20). I opted to land Runway XX with the tailwind due to being unfamiliar with ZZZ1 and the trees on approach end of Runway XY which would've required a slip and a steep approach to final. Touchdown on Runway XX was uneventful (on centerline and not in a crab) and I had proper crosswind controls (right wing down; left rudder). Upon rollout; I felt the plane push to the left and the nose veer to the right. This occurred at midfield in the vicinity of a large break in the trees. Presumably the wind gusted; accelerated through the gap in the trees and induced the incident. I applied corrective left rudder but it was ineffective due to the slow speed. I then applied left brake and even created skid marks on the runway but it was inadequate to stop the aircraft from veering to the right. The tailwheel then began to skip and eventually one of the springs sheered and twisted due to the side force. The aircraft then experienced a runway excursion and departed into a nearby tree line at approximately 10-15 knots. When the aircraft came to a full stop; I then shut down the engine; turned off the fuel and electronics and then safely departed the aircraft. No injuries nor damage to other persons or property. The aircraft was then pushed back to parking in the aircraft hangar and was defueled.