Excuse me, is this calligraphy an original by Liu Bingsen?

It smells like Liu Bingsen, although it is different from later calligraphy (especially signature). Later, Liu Bingsen's official script was flat, this one was slender and rigorous, but the brushwork was very close.

The inscription was written in the year of Jiayin, and the estimated year is 1974, so I think it is more likely to be genuine.

Because I don't know much about Liu Bingsen's growing process, I only read some of his later works, but I haven't seen his early works. This is just my personal judgment. The following picture shows Liu Bingsen's works found on the Internet: