Thanks for the kind words. Glad you enjoyed it.

"I've got a regular D-18, 1969 vintage. I recently replaced the pickguard, and toyed with the idea of putting on a tortoiseshell replacement piece rather than the black, just for the hell of it, to look good and just a bit different. (The original was, of coure, black.)"

My take on it is this -- if you've already replaced the old pickguard then the probability that either the new black or the new tortoise would alter the value is doubtful. It's no longer original either way. But I don't think that matters very much to the overall value anyway. I'd just put on the pickguard you like the looks of best. Pickguards are easy to replace.

I'd do it. I like the tortoise better than the black. That's just me.

"I put on a new black pickguard ~ but if I had gone with the tortoise instead, would people be fooled into believing my Martin is even more valuable than it is? Enlighten me please, I don't know squat about this stuff."

Now, to tell you way more than you want to know --

The short answer is, no, it probably won't fool anyone into assuming that your guitar is worth more.

The reason is this...

... sure, the "V" (vintage)and "GE" (Golden Era) series of guitars that have been made for the past decade or more have the tortoise pickguards -- so it would look more like them. BUT the 16 series as well as a short run Shenandoah series also sported the toroise pickguard and both of those are actually more "economy" models.

While I'm at at, let me also ask about the sunburst-top Martin dreads. I've only seen one, ever, and at first I just assumed that it was a nice old Gibson or something, not a Martin, until I got a good look at the headstock. These instruments are obviously pretty rare, but I'm curious about just how rare, when they were produced, etc.

The sunburst has been around for a VERY long time on both Gibson and Martin. Here's my understanding of the story. I'm sure there'll be someone who paid more attention in class and will corect me if I'm wrong...

The sunburst was first used on guitars as a measure to allow the maker to use top wood that had a visual (but not structural) flaw in the wood. My understanding was that Gibson did this first.

But the visual caught on. Folks liked either the implied patina or the dressed-up look (depending on who you talk to). As people actually wanted a sunburst, more were produced and Martin followed...

...but Martin did what is called a "shaded" top instead. If you look closely at a '30's Martin "sunburst" as compared to a Gibson, you will quickly note that you can se grain from edge to edge on the top. Martin's "Sunburst" was not opaque like Gibson's.

One other thing that this caused, in terms of difference between a Gibson and a Martin sunburst -- Gibson's 'burst is a lighter center around the bridge that is very generally the modified triange or egg shape of the outline of the lower bout.

Martin's sunburst, on the other hand, has continued the practice begun with "shaded" tops -- it follows the outline of the whole top. This means that a sunburst Martin dreadnought has a sort of weird-looking lighter modified figure eight in the cienter of its 'burst.

You'll notice that most of the boutique guitars produced today will do either a sunburst (Santa Cruz's VJ comes to mind) or "shaded" (Collings is, to my mind, the ultimate in shaded tops -- they've refined them to an incredible degree, as one might expect from their perfect finishes)

"(You'd probably be a little unhappy with mine, too, if we were ever to make an unintended swap. While my guitar sounds just great, it's a bit less than perfect cosmetically. All playing-induced wear and tear ~ nothing that wouldn't have been prevented by a Richie Havens-style oversized double pickguard ~ but the scratches and itty-bitty gouges are there for now and ever.)"

LOL! Actually, I LOVE a well-worn guitar. My Gibson LG2 has been in my family for 42 years during which time it's been treated as a campfire guitar, taken trips in the back of our '61 Ford Falcon station wagon (piled in with us six kids), and finally suffered a top crack that only the adjustable bridge held together. I had a guitar builder repair that and, to this day, that's still my favorite guitar in the whole world to play.