HiFi Kit Building- have you ever built any hifi gear?

Not audio. In the late 60s I built an Eico VOM.

Built a Dynaco Intergrated amp in college and a Bob Latino 2 channel tube amp about 10 years ago.  Both kits performed well.  Great learning experience.  Highly recommend giving it a try.  On a side note -- Sold both after a few yearsof use resulting in a very low cost / high performance / highly enjoyable experience. 

There is not one item that remains as the original factory spec being used in my audio system.

All audio devices in use are substantially modified audio devices that, under the hood, no longer represent what the original design brief set out to achieve.

Then there are the custom-designed, commission-built devices.

What can't be seen for being tangible as a result of the designs in use are the very long-term relationships developed between the designer/builder and the end user. 

Such long relationships are much more attractive than the music that is the result of the encounters are able to create. 

TT levelling platform, shelving, absorption panels. More of a woodworker than electronics.

I have built lots of speakers, turntables (not arms), cables, and electronics.  Hafler amps and pre-amps, Dynakit pre-amps, tuner and amps,  Even a Scott integrated SS amp in the 1960s.   Shelves, isolation bases, amp stands...  Pretty much everything except a phono arm, cartridge and digital equipment.