Scratch Build.  SLS Block 2 scale.  This is in experimental stage w/Rock Sim 9.  Please feel free t' download and tweak it.  Any suggestions, improvements or fixes are most welcome.

As it is now, t' rocket requires at least two 24mm F engines, or three 24mm D engines.  I have attempted t' provide a wide range o' engine mix options.  There are five 24/18mm engine tubes and two 38/29/24mm engine tubes. Aye aye! Neckin' down t' 18mm or 24mm o' course requires an adapter. Avast, me proud beauty!  A customizable mass object is located in t' nose for adjustin' CG. Avast!  T' rocket simulates as excellent stability and low weather cocking.  

A full engine complement, me bucko, usin' t' lower impulse engines that match t' non-adapted engine tubes, arrr, consistin' o' four Estes D11, shiver me timbers, two Contrail G300 SRB engines and one Aerotech D13W-10 with a 150g CG ballast yields 2150 feet altitude. Ahoy! I am workin' on improvin' t' 24mm engine performance, but t' drag profile for t' build limits this.

Basic low flight with two Aerotech F12J-5 engines = 720 fft.

Basic low flight with three Estes D12-3 engines = 250 ft.