Several web sites will tell you the date of manufacture from the serial number. Just search for "conn serial number" and a bunch of options will show up.
As for model and value, no clue.
JP/Sterling 377 compensating Eb; Warburton "The Grail" T.G.4, RM-9 7.8, Yamaha 66D4; for sale > 1914 Conn Monster Eb (my avatar), ca. 1905 Fillmore Bros 1/4-size Eb, Bach 42B trombone
TubeNet has a lot of members with a lot of knowledge in just as many permutations as there are members.
Your photos may contain information that one or a few will recognize as unique for a certain model, but in general front and rear photos taken along an axis perpendicular to the main plane of the tuba are most helpful. That is: photos that emulate the blueprints from which the tuba was made. Artful angles are less likely to promote a general recognition.
17" bell Eb, not very common. The bigger bell ones, at least, LOOK great and have a nice sound but don't really get it done intonation-wise- flat low Eb and D, sharp Eb and D in the staff, very flat F in the staff,... Low C is a great sounding and feeling note, Bb is pretty bleh, B natural might not exist.
Before 1917, by the company name. You'll need the serial number to tell which year. Eb. Conn did not yet have formal model numbers yet, and even then they can be confusing, because they sometimes re-used the numbers for very different instruments.
Instead of talking to your plants, if you yelled at them would they still grow, but only to be troubled and insecure?
I can tell you for sure that your horn was made before 1915 under the direction of Col Conn himself. That is the year Conn sold out to Carl Greenleaf and everything made after the change in ownership was ingraved with "C. G. Conn Ltd". The letter model designations started in the early 1920's. All the horns from that era normally have the tuning slide as part of the leadpipe between the mouthpiece and the valve block. This one doesn't have such a configuration leading me to think that it may be a an Eb New Wonder Model an Eb American Model three valved front action bass or an early experminatal prototype of the 2J or 4J. These were all being produced around 1902 or so.