Our shop uses and recommends the complete King's Officer's Bushing and Recoil Spring Guide rod kit, although the bushing is available alone. I believe that Ed Brown also has/had a strengthened bushing in his catalog for the Officer's - I think it is a drop in, if memory serves me correctly. Check with
www.Brownells.com.
The King's bushing is "oversized, Gunsmith's fit", but this does give you a strong bushing and an accuracy improvement all at once in most guns. Mine had to be fitted to both the slide and barrel, but it works great. The recoil spring guide rod, spring and plug work great as well - no possibility of shearing off the "tab" on the standard Officer's recoil spring plug.
With the King's kit, my Officer's has always been 100%. And your "bushing wrench" becomes any adjustable wrench - the King bushing has flats milled on each side.
Warmly, Col. Colt
"Beware of Counterfeits & Patent Infringements" - Samuel Colt, from a mid-1850's Colt Newpaper Ad. More True Today than 150 years ago!