FSI Echo 1 question

[scigs30]

Reading another thread I saw this bird and I became interested in building one. I know it uses a larger motor that is no longer produced. If I build the actual kit, could I just make an adapter for a 18mm motor? Or do I have to replace the entire motor mount?
http://www.oldrocketplans.com/fsi/fsiMRK-15/fsiMRK-15.htm

[RWmarlow]

I built one with 24 mm mounts...that way it can be adapted to 21mm (Hey one can dream) or 18mm..It's neat "feel good" kinda rocket too

[scigs30]

I would like to build the actual kit without replacing the motor tubes if possible.

[RWmarlow]

the adapter would be the way to go in that case...semroc sells a coupler (CR-78L) that fits the ST-7 inside the ST-8F tubing or you could peel an AR-2050