same old story for me.  couldn't find one so i made one.  many test fits, i like this one best.
screw it how you want, i'd suggest using non-countersunk screw with washer or a washer head for the sides.  i just put the deck screws in for a picture
print it how you want.  i did 0.6 nozzle, high flow petg, i'll let you know how it goes after this coming winter, '26/27
holes are 4mm, i printed 4 walls, 10% infill 4 top and bottom layers, plenty tough for my use case, could probably be super strong with nylon fibre material or abs/asa fibre