I have read this thread and the responses to your questions. The may be a limited edition with only a small number made but it is not a Huebler Custom.
Cues that were built as Customs were marked under the cues bumper Custom Shop By Huebler or Huebler Custom Shop and there would be a date. The marking on your cues butt identifies it as a production model made during the 1990's, before that logo was used they used Huebler USA and this logo was used starting in the early 1980's. Before that logo was used the logo was horizontal and it just said Huebler, and the earliest cues were marked with a H-?, depending upon the model number some were marked H-2 or other numbers.
I actually had one of Paul's earliest designs, and I bought it brand new at Cue and Cushion in Overland, Mo in 1974 or 1975.
I hope this helps, and I am positive on the information I have given above.
Take Care