There were a number of incremental changes in the design and construction of the OM-1 over its production life. All of those changes were incorporated in the OM-1n.

I think you will find that repair people like John Hermanson will recommend the OM-1n.

In addition, the OM-1n shares the Hot Shoe 4 with the OM-2n, although Hot Shoe 4's in undamaged condition can be hard to find.