Iv got a 1187 compact 20 gauge for my 7 yr old and its still to long it has a synthic stock can I buy a wooden stock for a 870 20 gauge to cutt short to fit?? Will stock inner change on a 1187 to a 870?? Can't seem to find a wood stock for 1187 but I can find them for the 870! Please help before I waste money. Thank u