hi! sorry for the delay in the answer!
i took some cheap fake leather gloves (normally you can find it on dollar tree or cheap stores, i have mine on a bazar of my city) and took the fur lining, to make them thinner!
then i made the arm part as a separated piece, i patterned the piece like some trapezoid, made it first on eva foam, then sew the fake leather covering the whole piece and sew a pair of clicks (corchetes in spanish) to put the arm piece more easily. Also, I glued the buttons and then sew them to prevent falling off.
thank you for your interest! hope you find it helpfull!