Probably not if it's the doll I'm thinking of. In the early 1970's, while Buffalo Bob was touring college campuses, there was an album called HOW TO BE A VENTRILOQUIST, which had Buffalo Bob and a Howdy Doody marionette (more like a dummy than a marionette) on its cover. That particular Howdy looked kinda garish in comparison to the Howdy people remember from the 1950's IMO.

And no dolls were ever used on either the original or revival shows anyway. All of the non-human characters were marionettes (operated completely by a set of strings), not puppets (smaller than a marionette and usually operated by hand, such as Shari Lewis' Lamb Chop) or dummies (larger than a marionette with joints installed, with a moving mouth operated by the ventriloquist, such as Paul Winchell's sidekick Jerry Mahoney).

Hang on to it nonetheless - it may be worth something down the road. If you actually want a toy that was marketed during the original show's run, there are plenty to be found on eBay. Many of them are inexpensive, however, the Puppet Playthings marionettes, which were wildly popular, and the Ideal Howdy Doody doll from the 1950's (IMO, the closest replication of Howdy) usually command some serious cash (in the range of $100 and up), especially if they're in mint condition.