No, this Crimson Trace Front Activation Green Lasergrip is designed for 1911 model pistols and would not be compatible with your Ruger MKIII.
The Crimson Trace Front Activation Green Lasergrip features user adjustable windage and elevation adjustment screws. You can read the user's manual linked below to assist in making adjustments to your laser.
https://www.crimsontrace.com/on/demandware.static/-/Sites-crimsontrace-master/default/dwb8671980/manuals/general/laser-sight-general/laser-sight-user-guide.pdf
Yes, the Crimson Trace Master Series Rosewood LG 903 1911 Bobtail can be found by using the link below:
https://www.opticsplanet.com/crimson-trace-master-series-rosewood-lg-903-1911-bobtail-government-commander.html
As long as the grip screws measure 3 & 1/16th inches from center to center and it has a single side safety, any of our full size 1911 grips will fit, such as the LG-401G.
No, Crimson Trace does not offer laser grips for the 1911-380 from Browning and I am not aware of any laser grips available for that firearm.
No, unfortunately we don't make a laser to fit the Browning 1911-380.
No, this will not fit the Browning 380.
Yes, it should fit.
It should as long as your rock island is the same dimensions as a standard 1911, you shouldn't have a problem.
As long as it is single stack and follows the same dimensions as the Colt government/Commander models, it should work.