Do you have graphic or technical drawing skills and or software? If not, I can make you some scaled PDFs. My drawings are in Illustrator (an odd platform for technical drawings, but it works for me!)
Front end on the 7 is Triumph Spitfire and Herald, Steering Rack, Uprights, Brakes. You could probably make the Spridget parts work, depends on how authentic you are trying to make it. You'd have to work out A arms and associated geometry. Spridgets use lever shocks, with the lever acting as the upper locating arm. With the Spridget stuff, you'd still have a period correct "special," just not quite original.
Have you visited the Locost USA forums? (http://locostusa.com/forums/) Tons of build information there, and as many opinions. The main thing you might run into in discussions regarding building something kind of original is, "Why bother?" There are better, cheaper, easier to find components, as well as easier ways to build and complete your project. Personally, I'm taking a similar route to yours. Why? Why not! It won't be a "real" 7, and it won't be the fastest 7, but it will be fun, and it will be mine, that's reason enough.
Message me about drawings and what file formats you can work with.