Taking a look at it though, it’s got a pretty solid looking umbilical termination on it, but the propellors look tres tres weak- narrow cross section on the blades. It might be a blessing if you have to replace the thrusters on it.
Can you please send me an image of the umbilical top side connector and also the electronics within – you’ll maybe either need to control from the top of the umbilical with some voltages, or perhaps there are transformers and crude PIC microprocessor within the sub crate? How long an umbilical did you get with it?
Cover all the seals in scotch-cast, kote/amalgamating tape, that thing might go down 100-300ft if the thrusters dont leak on you first.