At least inspect the shoes for wear before replacing them. These brakes aren't super strong at their best, and new shoes won't make an improvement unless yours are damaged or worn out.
The shoes have to match the drum radius exactly for maximum braking, and old shoes are pretty certain to have worn in to match the drum. Reradiusing new shoes is either a job for a brake shop with the antique machine and someone who knows how to use it, a messy and dirty home job gluing sandpaper into the drum, or not done. New shoes with different radii than the drum will be really ineffective.
I don't think any Honda shoes in the 70's used asbestos but be very careful with the brake dust just in case: when you clean the drum out, don't blow it out, wash it out with soap so the dirt goes down a drain not on the driveway to dry up and blow around later.
