Most likely ABS but possibly PLA. The ABS will take the acetone treatment but be careful because it is basically melting the plastic. PLA does not melt in acetone but is a food grade plastic that will deteriorate faster outdoors(it can be composted). So hopefully they are not PLA
You can also melt ABS scraps(like the pieces you removed) in acetone and make a slurry that can be brushed on the finished pot to give the glossy effect like the acetone bath. it can also be used to glue pieces together and such because when the acetone evaporates the plastic will be hard again.
Dont mean to go crazy I have just done a lot of research in the hobby and a lot of geek translation to be able lay it down in terms most people can understand.