Just throwing this out to you as a possibility. The seller is an FFL dealer who apparently doesn't know a whole lot about this type of firearm, and who says he will be listing several more in the near future. I wonder if he may have taken in a collection from a deceased collector to sell on consignment, and the guns were stored with the bolts removed and stored separately to discourage theft. I've met a couple people who do that. This dealer might have just taken a pile of guns and bolts from the estate and tried them out until he found one that fit. He may still have the correct bolt for this gun in another Springfield rifle. A call or e-mail to the dealer is worth a try and certainly cheaper than headspace gauges or replacing the bolt or bolt handle.
