Some of the more established shipwrights or marine
mechanics may have a few tools for your sort of job, but they would likely be highly prized and not sold (or lent!) lightly.
Have you considered making a dummy set of wrenches out of (say) plywood
or scrap lumber
, measuring the distance between the faces of all nuts accurately, checking that it will actually do what you want and then taking it to your local engineering workshop. Some plans, diagrams, measurements, photos and notes may not go astray either.
Mine does high quality and very reasonably priced work, though they do seem to expect a bit of a chat about my boat. Modern engineering could be quite a high stress job so a relaxed approach may also be also be part of the deal.
I would not be surprised to find a custom fabrication to be cheaper than a mass produced piece of junk...