I have a 77 pig and a 94 FZJ75. I was actually thinking just yesterday while driving the 75 that the steering wheel reminds me of the one in the pig. Not sure what the stock wheel looks like in your 70 but here’s a pic of mine.
I also just bought another steering wheel for the pig as mine isn’t in great shape; probably what prompted the comparison. These are difficult to find in good condition so it could get a little pricey.
You can find the FJ55 steering wheels on eBay. It said they are refurbished. Who really knows. But they are affordable if good work was done. The only thing I’d be curious about is the diameter between the two.