lols just posted when you edited the numbers!

First engine no seems Accurate for a very early series 3.

Second Serial is Perfectly Accurate. And yes the starter is not original,but it is correct in style and accurate for this mower smile

Third Serial,seems a little early and would probably be more suited to a Model 5 Series 2...BUT research and complete accuracy for Serials is sparse for the Model 5 Series 3...But I would leave it as is for now and maybe make it your last restore,and more info will come to light in the future regarding its accuracy.

Yes I like the Blue too...

All mowers are valuable to their owners. But since you asked the question...No they are not valuable in monetary terms...Yes they have historical Value,but they are not rare. You will have no trouble in restoring these to there former glory without damaging the historical or monetary value.... infact it will more than likely cost you more to restore than what its worth....but as I said,The owner holds the mowers worth in his own mind!!!!