The buttstocks will interchange on the respective receivers - to a point.
Keep in mind that Marlin fits every buttstock to a particular receiver, then numbers them so they can be re-united after finishing, so:
*minor re-fitting may be required for one or both stocks
*neither stock will be serial numbered to it's receiver any more
*the recoil from the 1895 with the 1894 buttstock may be more concentrated - my 1894's BP has a smaller area than my 1895's do, even though the wrists are the same.
*the inside of the 1894 forarm doesn't have room for the M1895's magazine bulge, and would have to be inletted there (thin/iffy)
* the two barrel thickness/countours differ, where they are inletted into the respective forearms.
That said, I argee with Swampy - I wouldn't ditch my passed brother's gun, either.
I'd slap plastic on an 1895, and worry about paying for it later.
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