I am 99 percent sure the stock of the Model 1400 Mark II is OK BUT the Winchester Components Parts Catalog gives the two models different Parts numbers, and even differentiates between the Walnut and the Birch stock. This could be because the Model 1400 k II had a walnut stock and the Model 140 had a Birch stock with differing checkering I have not checked the stock of the Canadian Model 2200 (which was not checkered.  The Model 140 forend is back further over the receiver, and the Model 1400 Mk II may not fit as well.  As well the parts numbers are different for the two models and timbers and checkering.

I would not use the Model 1400 Mark I stock and definately not the Forend

I can send photos if you wish.

I would look to Midwest for supplies.

Keith