OK so here is my only concern:
The Reeves 225 is a pretty loud amp, but I suspect you may wind up pushing the output section into distortion, and somewhere I seem to remember reading that the output distortion of Hiwatts is not the greatest.
IMHO, These amps are really designed for max clean power with just a touch of breakup available in the preamp, and I have never really pushed mine so I didn't know one way or the other. So I pulled out my 79 DR103 and hooked it up. (Sorry but my Reeves 400 would easily blow my speakers). The voicing of the DR103 sounded almost exactly like the Custom 225 demo I posted earlier in this thread, except a bit deeper bass cause I have some huge speakers ported in the high 20 hz region. When I cranked the amp up, the distortion did not come on smoothly or evenly across all frequencies. First low notes distorted, and as I increased the output the distortion went up the range of the instrument. The quality of the distortion was a bit buzzy right away. By the time sufficient volume was reached for the E (2nd fret D string) to break up, the open E string was pretty farty.
To compare I hooked up a 76 Matamp GT120, which has a similar deep low end response to the Hiwatt. The output distortion comes on really smooth with this amp. When the distortion first starts you barely notice it and it occurs pretty much at the same volume across the range of the instrument. As volume increases the distortion slowly becomes more and more gnarly.
So based on my little experiment, I am confident a Reeves 225 would be a fine amp with two caveats: 1. You like the natural tone of the amp demonstrated in the video posted earlier in the thread, in particular the amount of low mids in the sound as the Reeves/Hiwatt tone stack doesn't really boost low mids. 2. You have speakers that are large and efficient enough to meet your volume requirement without the need to push the output of the amp into hard clipping.
Despite the fact that my Hiwatts and Reeves amps sound very similar to each other clean, there is no guarantee their output sections will behave the same under overload. If you have pushed the output of a Reeves 225 into distortion and achieved different results than I did with my DR103 experiment, please comment.