Just a few months ago I bought a 1920 Speedster that had been completely done in 1985, driven very little here in sunny Southern California (probably never seen a drop of rain), then parked indoors in 1995. It has a lot of goodies such as 5 T wire wheels, exterior oil line, Ricarda Waukesha head, Ruckstell 2-speed rear end, and a high dollar red paint job that was excellent throughout. Obviously, somebody had spent serious money building it. After negotiating from the $6,000 asking price down, I paid $5,250 for it, and had the car running fine after 2 days of tinkering.
Tires were dry rotted, times 5, so there went the first $700 as I also bought new tubes and rim bands. A new battery followed. Then the first test drive revealed a front end so worn that I wonder if anybody could have driven it even around the block. Just horrible. Leaking water pump, broken crank shaft pulley bolt, some electrical gremlins. A home-built exhaust system that was just ridiculous, cracked monocle windshield glass . . .
Then I bought various books on the subject and looked at all the photos at Northwest Speedsters. Afterward I knew I didn't like the style of my car, and the red color I hated from the moment I first saw it.
So I took it apart and started stripping . . . everything off. What a slave job. Discovered that the base plate was plywood and hated it. Hated its plain, rectangular shape as well. Disliked the laminated dash board. Disliked Phillips screws, modern carriage bolts, the galvanized fuel tank, the repro instrument bezel . . . you get the picture. Basically I started over from the base plate on, building it differently, still on a budget, but those things add up in the long run. My goal is to build it along the lines of the Yellow Peril, but aged, distressed, and in all black. I want it to look like it had been built in period. I will get close, but it won't be exactly the way I envision it.
If I were to do it again, I would start with aged hardwood planks to make up the floor. Since that's step 1, the foundation, everything that follows can't make the car right. So I understand that you would want to build it yourself. Get informed, and start with erasing the term plywood and Phillips screws out of your brain. Build it like it's 1927/'8/'9 or so. What we are doing is cheating, so let's cheat correctly.
Here is my personal favorite. You can see that it was period built, and not with parts from Rootlieb:
http://www.tomlaferriere.com/1921_ford_model_t_speedster.htm