Here’s a post from the forum re: inductors:

Ever since I started this hobby, I was always interested in the black art of the inductor. Hardly anyone seems to know what value certain inductors were and from what I have been reading, two measurements seem to be the most important: inductance and resistance. Based on this, I purchased and tested a number of inductors from part numbers mined from the forum and some guesses I made when looking at the spec sheets.

Before you read any further, from what I have been reading, the Fasel inductors Dunlop sells are actually spec’ed pretty good. Although higher than the magical 500mH, they do hover between the 500mH-600mH mark with very low resistance. The yellow seems to have more resistance than the red, but not by much.

The 42TM024 just happens to hit right around the 435mH mark, but with high resistance. The 42TM022 is very versatile with 252mH, 800mH and 190mH in different combinations with relatively low resistance.

The 42TL024 comes in with 1.1H at the primary.

S = secondary
P = primary
o = outside lead
m = middle lead
R = ohms resistance

42TM024
S o+o = 435mH 160R
S o+m = 102mH 76R
Possibly good for midrange circuit??? Possible use in wah?Huh

42TM022
S o+o = 252mH 46R
P o+o = 800mH 60R
P o+m = 190mH 32R
All kinds of uses?

42TL024
S o+o = 196mH
P o+m = 1.1H
http://www.diystompboxes.com/smfforum/index.php?topic=33725.0
Close to 1.5H but not quite.

42TL021-RC
S o+o = 161-187mH
S o+m = 36-43mH
P?Huh? no reading
http://www.diystompboxes.com/smfforum/index.php?topic=22409.msg141895#msg141895

Fasel Red 580mH 15R
Fasel Yellow 540mH 23R