The lack of the "in God We Trust" motto in the back is normal. The phrase wasn't added to paper money until later in the 1950s, so a year 1950 bill would not have it.
If it is really in good shape, it probably is worth more than $50. Paper money isn't as valuable as say silver coinage, because silver is more valuable than paper. Do some checking on the web. E-bay may give you some idea as to value, but not always. Your best bet would be to take it to a couple different coin shops and ask them. Be up front with them, and tell them that you just want a value out of curiosity. If they both give you about the same price, that is probably a good estimate of worth. By the way, some OLD currency (1800's and early 1900's) is worth quite a bit. Take care.
Unless it's a 1950E series, you'd probably have a difficult time getting more than face for the note, unless it's in a very high grade. If it's average circulated condition, any coin shop would probably just tell you to spend it. Then again, more than one opinion is always a good idea. Of course, it's gonna depend which district it's from and whether or not it's a star note, low serial number, etc. Hope that helps.