This is the second time I've said, "Back in the day," and it's making me realize how old I'm getting... Anyway, back in the day, you could purchase the plastic fuse block, P/N 24311-01M00 (now discontinued), through your local Nissan dealer. However, all you got was the plastic block; it didn't come with any of the terminals with it. So, those wires with terminals that were good would have to be carefully removed from the old fuse block and installed in the new fuse block. Any wires that had bad or damaged terminals would have to be cut and new terminals installed on the wire. The new terminals would come from a Nissan terminal and connector repair kit that was force shipped to the dealers when it came out. It was made by Kent-Moore and it was very expensive! It had assorted empty harness connectors, assorted terminals, pin tools and weather seals. Each part in the kit had a Kent-Moore part number. Now, what the part number was for those particular terminals, I have no idea. If you have an old Nissan dealership near you that was around in the 1980's, it's "possible" that they may have some terminals in their kit. I wouldn't hold my breath, but you could check with their parts department, as that's where they probably keep the kit, and hopefully you'll get a patient parts man with not a lot to do at the time who can help you. You could try getting in tough with Kent-Moore to see if they can help you, but I would suspect the chances of them still keep those parts in stock are slim. As already suggested, you could try finding an old B11 in a junk yard and cutting out the fuse box (make sure you get as much of the harness as possible, preferably at least 8"). Then, you could either remove the individual wires with the terminals (as many that you need) and solder them to your existing wires in your vehicle...or, splice in the entire fuse box to your vehicle.
Now, unless you are restoring this to concours condition, what "I" would do is simply cut the two wires to each fuse cavity in the fuse block (one fuse cavity at a time) that have damaged terminals and install an inline fuse holder (make sure the wire of the fuse holder is at least the same gauge as the wire of the vehicle harness) with the proper fuse rating for that circuit. It'll make the repair a whole lot easier and quicker than trying to find OEM parts: