1939 John Deere LI id and value

I just looked at a 1939 John Deere LI and could use some guidance.
First, is there a way to confirm 100% that this is an LI? I am told the tags didn't start saying LI until '41. Everything I can observe and everything the current owner(owned 35 years) told me point to it being an LI, but I need to know if there is a way to be certain.
Second, what is it really worth?
It is a 1939 LI with hydraulic pump and sickle mower. The mower appears to be all there and, aside of the sickle sections being worn worse than I have ever seen, in decent shape. Tractor is partly disassembled(nothing major but would take 4-6 hours probably to hang everything back together). Front axle does not appear to have ever been damaged but does have a couple chunks of iron welded to it to stiffen it. Tin is quite beat up but certainly saveable. It has also had several splits(6"-8") that were welded but the welds are pretty ugly. The tin that covers the drive shaft is missing. The mag was stolen and the air cleaner is also gone. Am told it ran before the mag was stolen. Gauges are 'working tractor' quality. Fuel tank has a very small puncture that will need repaired. Steering wheel is typically cracked and broken. Fenders are the straightest piece of tin and are solid. Seat is aftermarket and the seat mount/springs appear homemade. The pedestal for the steering shaft was cut off and rigged to mount in the middle. Drawbar is missing the roller. Tag is good. Rims are in pretty good shape. Front tires are auto temporary spare tires. Rear has no tires.
Let me know what you think. Thanks
J

The LI and LA usually have the model stamped on the top of
the rear axle.

Maybe you should consider falling in love with one of the many other very nice brands of tractors.

(quoted from post at 19:47:56 11/09/14)
Maybe you should consider falling in love with one of the many other very nice brands of tractors.

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I'll stick with green and yellow.

If you have the serial number your in luck because a early edition of the Two-Cylinder mag has a list of the early LI serial numbers.

(quoted from post at 09:10:58 11/10/14) If you have the serial number your in luck because a early edition of the Two-Cylinder mag has a list of the early LI serial numbers.

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I'm having trouble reading my own writing but the serial # is either 628195 or 628495

If the Johnny Popper site is correct and it is 195(I'm 90% sure that is what I scribbled) then this tractor is indeed an LI.
Now I just need to know what it is worth being in what I consider pretty rough condition.

If it is #628195 it is a Hercules engine LI. The other number isn t.

(quoted from post at 11:55:56 11/10/14) If it is #628195 it is a Hercules engine LI. The other number isn t.

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What are the easiest ways to identify if it is the correct engine? Dad had a couple Ls but they both had LUC type engines.

From what you describe <$1000 The mower is 7d and somewhat rare with hydraulic. Can be exspencive to restore!!! I feel the demand and price for these are slipping.

were is this LI at?