I'm afraid I can't help on the Motioncraft identification, but I congratulate you on having a good riding bike that's a bit unusual. You probably don't see another one of these every day!
As far as being "nuts" for liking it, far from it. There are several criteria for judging the worth of bicycles, and every judge has a different system. But for what it's worth, I score you're bike thusly:
1. Functionality as a tool. Bikes are fundamentally a means of locomotion, and your's locomotes fine. Index shifting that goes on the fritz, brakes that squeal, wheels that wobble are typical faults. No deductions.
2. Aesthetic appeal. I haven't seen it, but any bike with a full sloping chromed crown and nifty lug work is worth looking at. Tentatively assign a full score.
3. Sweat Equity. Bikes get more interesting the more stories that are associated with them. Every drop of perspiration on the top tube makes a bike more special. It has something to do with the memories associated with them, and a bike with the battle scars of long and honorable service is far more interesting in the Adams scoring system than a pristine wall hanger. And any bike that traveled the Malay Peninsula gets full marks.
4. Mojo. The toughest category to score because mojo can be altered by outstanding scores in other categories, or can be hurt by overdoing it. For example, mid level Hetchins have excellent mojo, but the super fancy examples lose mojo points for trying too hard. Also, operator error can hurt mojo scores (crashing in the parking lot before the ride leaves causes a major mojo reduction, regardless of how cool the bike. Trust me, I know). Some bikes score high in the Mojo category because of their maker and others get it from appearance, rarity, etc. Since you will always be the only person on the Tuesday night ride on a Motioncraft, you're bike has good mojo. However we have to deduct 1/2 a point for not having Campy dropouts. (I said judging criteria were idiosyncratic!)
So we see that you're bike scores 9.5 out of a possible 10. As I don't have any bike that scores over 7, I would ride your's proudly. Congrats on your faithful steed.
Tom Adams, Kansas City
Amongst my bicycles I have one that has been a good mate over the years. I purchased it in 1981 in Singapore whilst I was working there as a member of the Singapore Symphony Orchestra. (Honestly I was...) I call this machine my "little black bike." I have ridden it more my miles than any other I have owned, including rides well up into the Malay Penisula. The frame has very severe geometry but is a sweet ride. The bottom bracket is marked "champion tange," the lugs are "pointy" with very pretty with cut-out centres. It has a fully sloping fork crown that is plated. It is clearly very well made; obviously Japanese in origin. The dropouts are Shimano. When I purchased it (new) it had transfers (decals) that identified it as a "Motioncraft." Am I correct in thinking this may have been made by Bridgestone? It doesn't have the cache of my Mercian, Carlton or Hetchins but seems, at least from a ridability (is that a word?) view-point to have some merit. I cherish this machine: am I nuts, or does it have any value beyond my own emotional attachment? Lawrence (getting sentimental in Tacoma, WA) Bradley