Keep in mind that that model was made from 1927-1969. I suspect metallurgical changes along the way. I'm not real eager to see how a OP made in, say, 1928, would fare with a constant diet of hot Buffalo Bore or Underwood loads.

But I think one from the 1950's-on is certainly okay for reasonable Plus P use.

Look at what Colt said for the much smaller Cobra and Detective Special: They warranted both with Plus P, but warned to return the steel guns for factory inspection after firing 3,000 rounds of Plus P and the light alloy frames after just 1,000 rounds. Frame stretching was a concern and writer Massad Ayoob once stretched the frame on a Bodyguard .38 with just 500 rounds of Plus P. I forgot if it was an alloy M-38 or the steel M-49. He's a member and if he sees this, may comment on that.

Keep in mind that after the USAF began using high velocity ammo in their S&W M-15's, the guns shot loose sooner and they begged for 9mm autos, hence the Beretta M-9 adoption.

The Colt Official Police is a tough gun and Colt has warranted it for high speed ammo since the 1930's.

But don't pound it all the time with Plus P and it'll last longer without repairs.

Plus P and .38-44 class loads are meant FOR KILLING and are not needed for normal range use. Of course, this also applies to .357 revolvers firing full Magnum ammo.

I'd usually carry a .38 with Plus P loads, because you don't know what might force you to use the gun in earnest. A big dog or rabid raccoon or coyote needs stopping right now, as does a human foe. Those in cougar or bear country relying on a .38 should carry Plus P. It's just common sense. But don't pound the gun all the time in practice with warm loads.

Be advised that most Colt .38's don't shoot to the sights and the cylinder timing wears much sooner than on Ruger and S&W guns. Famous pistolsmith Jim Clark told a friend of mine that he'd re-time his Python, but warned that in 500-1000 rounds of .357 ammo, it'd probably need re-timing again.

I think your Official Police will perform well with Plus P assuming that the sights are on target. You may need a good gunsmith to turn the barrel slightly to get it sighted-in.