The 5F1 is an absolute classic, standing at the beginning of a great history of guitar amp development. From today's perspective it is more than surprising with which simple equipment the guitarists had to settle in the late 50s of the last century.
Building notes: The kit gets build with standard components out of current production. Unfortunately, the chassis is not quite up to date and has some deficits to take care of. There is no pre-drilled hole for a protective ground connection. It may be allowed in other countries to fix the protective ground connection with the power transformer's mounting screws, but in Germany the protective ground connection needs to have its own separated chassis connection. Therefore it's advisable to add a hole in a favourable position for this connection to the chassis before starting the build.
The holes for the jacks are very small thus only Switchcraft jacks can be used. The problem is: the jacks are not isolated from the chassis and can not be mounted isolated with isolating washers, so the signal ground connects to the chassis at several places, which can lead to hum and ground loops. It's essential to adhere to the shown layout, then there are (almost) no problems with hum.
Schematic as PDF (2 Pages, DIN A4)
Layout as PDF (1 Page, DIN A3)
You can get the kit at the TT-Shop.
Care is necessary during construction! Even though this is a low-watt amp, the voltages used are potentially fatal. This amp is NOT a beginner's project!
A successful build requires that you can read (and understand!) a schematic diagram, you know how to use various measuring devices, and you have some experience working with voltages over 60V.