You got the right guy. Here I is. And yes, the Dorcy is a PR base.
I have made several of the PR bases with copper plumbing parts and all have worked flawlessly. Lots of copper mass for heatsinking. For a standard PR base, you will need to use the standard 1/4" copper piping. However, for a Maglite, you can use the 1/4" JUNCTION which is slightly bigger and fits the Mag socket with precision.
So..buy the following parts-
*1/4" copper piping(or 1/4"junction for Mag)
*A brass bolt 1/2" to 3/4" long. The head will become your contact and the threaded end will fit into the interior of the pipe base.
*A nylon nut(sized to brass bolt threads)that is a little bigger than the inside pipe diameter before filing & fitting.
*A short length of #14 copper wire.
Make the PR base by first fitting the nylon nut to the inside 1/4" pipe. A little filing will accomplish this. The nut should fit snugly into the pipe. Cut your brass bolt so that when screwed into the nylon nut, only a 1/8" or so of the thread end is left. Use a 1/16" or 3/32" drill to drill a hole all the way through the bolt, top to bottom. It's a little tricky but definitely doable. You may want to file the bolt head so it is a little flatter.
Now you will have to insert the nylon nut with brass bolt into the pipe and compare to PR base. Pipe + nylon/brass bolt when inserted should total approx 16mm in length. Cut the pipe at this length. The pipe will be around 11mm. The nylon nut with brass bolt head will stick out about 5 mm extra. So 16mm total. Cut the pipe so that your total base length will equal this.
Use the #14 copper wire to construct your top flange. Just curl it around the sized pipe and solder one end. Hold the other end with a small vise-grip(or whatever) then solder all the way around. You can adjust the flange diameter with a file later.
Drill holes, equally spaced in the pipe center section for the negative leads. Dropping resistors, if used, will be soldered very close up to the + led lead base. Use a heat sink here(a pair of needle noses will do). Then insert your 3 leds(maybe 4?). Put the unsoldered ends of the resistors into the hollow brass bolt. These will be soldered where they emerge from the base(bolt head). The negative lead of the led will be pulled into the drilled holes in the pipe and soldered to the outside. Oh, try and use the small wattage resistors here for easiest fit.
Voila. a copper PR base. Phew. Don't have a digital camera or I'd post a pic. Let me see what I can do here... Is this description clear or are you totally confused?