Pretty much - you have a few options though.
For a start, 2.6" to 29mm CR's should be easy enough to get hold of - PML and I believe LOC 2.5" tubing is very close to BT80 (as used in the executioner), the PML stuff certainly has the same ID.
A couple of CR's should do you nicely, and a length of 29mm tube.
Where you have choices is motor retention. Just about everyone has their own way, and it depends also on whether you're using single use or RMS motors. There are various commercial motor retainers available, but they might be a bit on the pricey side for a rocket like this. You need something to stop the motor moving forwards and something to stop it moving backwards.
You could install a thrust ring in the MMT, but that puts some constraints on the length of motor you can use. With SU motors, the accepted technique is to build a thrust ring out of masking tape, this butts up against the base of the MMT and stops the motor flying out the top of the rocket
RMS motors have the thrust ring built in.
The other side of retention could easily be accomplished with some simple hardware - you just need something to stop the motor being kicked out at ejection. There are many ways of doing this - t-nuts in the aft CR are popular, then you can use bolts with washers to hold the motor in. Not pretty perhaps, but effective.
https://www.info-central.org/infocentral.shtml might be a good place to look.
HTH