Did browning install polychokes on a-5 shotguns?

Yes they did, but only on special order request through the Gun Dealer. This work was done in St Louis at the Browning shop, but it is difficult to determine if it was done by Browning. There is no such thing as "Factory Installed poly chokes". Even if Browning St Louis installed it after the gun was made, it is still unoriginal to the gun