Have you looked at the Winchester Model 1886 "Extra Light Weight" (Miroku repo), chambered in .45-70? Mine balances and shoots well with the 22" long barrel (I have a Williams "Foolproof" receiver mounted on it). Though dscontinued, I still see new ones selling for $1,100.00 or so at various gun shows. Though it doesn't have a pistol grip, it does have a more comfortable "shotgun" configured butt stock.
Agreed, I have the same '86 and love it, the balance is perfect IMO I did have the 'light strike problem but did the rebounding hammer cancel and that cured that. My wife carries a Marlin 45-70 with a 20" barrel in her scabbard and that balances nice as well but has the pistol grip which I am not fond of but she is so who argues with a woman lol
