FWIW - I measured the 'front-lip' (tendon) thickness on three Krag side-plates, (one model 1896 and two model 1898's), with a vernier-caliper.

The Model 1896 measured approximately .131" to .132".

The Model 1898 plates measured .153" to .155".

The difference is about the thickness of two 'Business Cards'. I don't know for sure, but, more than just the tendon thickness could be involved.

Fitting an incorrect side-plate, by thinning the front tendon (lip), may disrupt the fit of other surfaces and angles.

Measuring is the best way, I know of, to "ID" these different side-plates. They are hard to differentiate by eye alone.

You can measure your 'new' plate and the one that came on your carbine to see if they are different models - (just burrs or .020 thousandths of an inch).

If you were sent the wrong plate, I am sure an email to David Stewart at "Granpa's Gun Parts" will correct the situation.

In the attached picture, the Model 1896 side-plate is on the Left. I have marked the center plate to show where I measured the thickness.

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