Despite being a ridiculously large cap fan myself, you should indeed return that if able.
Having experimented with huge poly caps that size in a SEX, they are too heavy to support themselves with just the hookup wires and a zip tie. You have to build some sort of physical support to keep them from pulling themselves apart. Without a firm support for the body of the cap, the hookup wires can pull themselves out of the cap. And the hookup wires are so thick it makes its difficult to get a good solder joint on them with the stock terminal strips and a normal soldering iron anyway. Had to resort to IR and large heat sinks in my SEX for reliable joints.
Since those hookup wires have already had enough violent force applied to them to break the wires off at the solder joints, there is a decent probability they have also pulled apart inside. So on $400 a piece caps, I wouldn't risk it.
If you got a good deal on the amp, IE paid the kit price and got the caps and other upgrades for free, it may be worth repairing. It looks like it already has a C-7X for the power supply filter, an Audionote volume control and it looks like it was built pretty well otherwise.
If you are driving ~300ohm headphones like HD650s, with that C-7X in the power supply you can reduce the output caps and final power supply cap to 60uf each for some more room under the hood and a reduced possibility of the caps pulling themselves apart.
But if I paid more than kit + assembly price based on the used retail value of those Mundorfs...I'd try to get my money back.