I found this engine in my grandfather's basement. Can anyone tell me anything about the model, its value and is it collectable? It appears to missing a needle valve. Is there anywhere I can get one for it?

it looks like an old mc coy 29.  the front has to be mounted in line with the head, a needle valve can be made simply by filing a 2" cap screw to a long taper by inserting the screw in a drill motor and as spinning file to a long taper. had to make meny of them as a kid.

Are they collectable and worth anything? I am working with Mecoa to see if they have a replacement part. If that does not work out I will try to make one. Any idea when this engine was manufactured?
Thanks

These were made from the early to late 50's in several sizes (.098,.19,.29, & .36) . Early were called Stunt & later ones Super Stunt . I have bought the needles from MECOA that are used on the series 21 engines ,they will work. You need to take the front cover off & place the intake upright ,the way it is now is for running it clockwise. Value is in the 40 to 50 dollar range .
Hope this helps,Max H.