Here's Opuntia pailana (hight 65 cm) and Echinopsis peruviana (hight 150 cm). Their plastic pots have broken rims from moving their heavy pots now and then. Not very nice to look at, so I'd like to re-pot them in traditional terracotta pots. Easier said than done ! I suspect that the plants might easily breake. If 'specialist cactus repotters' exists I don't know them. Maybe you have a brilliant method for doing the re-potting without risk of breakes ? Or is it simply too risky and I've better give it up ?