I think I would agree if you do a high-end fixed gear build, you will never get the money out of it that you put in. I would argue you would probably sell it for more money if you pieced out the bike and sold it as individual components. When I build up a FG I feel like I have much more connection to the bike than any of my high dollar road bikes. Actually I know I would never sell a bike I painstakingly researched vintage components and sizes to fit it together.

Back to your question, unless your trying to sell it, I think any cyclist who knows components could spot the quality of bicycle you have. Even if I walk past a beatup bike and catch a glimpse of "shamino 600" stamped on the headset I will look at their other components. From your point of view you have a much better built (not to mention..much lighter) bike than a republic.