Generally speaking, if your '86 has a serial number below 60,000 it is considered an early model. These rifles had a buttstock with a longer and thinner toe, like the 1876 model. The upper portion of the buttplate protrudes 2 and 3/8 " into the top of the stock. As the series developed the stocks became lighter and thinner with a less radical curve at the toe. There were problems with wood cracking and breaking at the toe on rhe early guns. I believe that the forends were the same throughout the series, with only slight variations. Factory "short rifles" have slightly shorter forends than standard ones do. All stocks and forends were of select straight grained walnut. Fancier wood was available on special order.
Hope that this info is of some help to you.
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