USA had Erector now the same company.

Cool. Hope the quality doesn't suffer.

 

Here's what I came up with, good for 695puff.
Guillotine variable capacitor, about 4x6 inches:

 

Mostly made in cheap chinese plastic now.

Too bad. We didn't have much $ growing up, but my folks made xmas a bright spot.

My father, a mechanic, used to bring home spare electrical parts for me. Once,
he had to replace the taillight blinker mechanism for a Thunderbird (the model
with sequential rear blinkers). This was a kind music-box device with leaf switches,
and the old unit had corrosion on the contacts. I disassembled the entire thing, cleaned
and lubricated it, attached 3 bulbs and a battery, and had it going on the workbench
nicely. I put it away, with thoughts of robotic applications. A week later my father
came to me with his hand out, asking for me to share it back, as a follow-on customer
with a faulty burned-up unit needed replacement, but couldn't afford a brand-new
unit (over $100).

https://www.ebay.com/itm/114454415647?hash=item1aa603c91f:g:pbUAAOSwhshfgH-P

At 1st I was hesitant, then pops added that I could do my part to help the family.
That was a moment of pride in my primary-school years that I'll never forget.

 

The 222 series condenser described along with it's complimentory parts posssible to compare the changes with the 722 series. in the General Radio catalog 1935 page 26
https://www.ietlabs.com/pdf/GR_Catalog/GenRad_CatH_1935.pdf

Reactance meter designed by Hazeltine a division of General Radio explains the correct process recommended by Hazeltine labs 1934
The instrument was deployed for quick measurement and adjustment and continued to be very valuable test instrument of radio builders.
note( uuF micro microFarad ) is obsolete we now use the term pico Farad, a pF is exactly equivalent to uuF

https://www.ietlabs.com/pdf/GR_Experimenters/1934/GenRad_Experimenter_April_1934.pdf