Yes, and don't call me Shirley (sorry, but someone was going to say it).

I apologize if any of this is duplicative. I found these: https://www.bulbs.com/Specialty_Bulbs/I ... sults.aspx, https://products.bulbrite.com/?Level1Ca ... CANDESCENT

and this: https://insights.regencylighting.com/st ... -bulb-bans
"General Service Lamp (GSL) Exemptions

There are a number of products that are exempt from the definition of a General Service Lamp and can still be sold according to federal law. (Note: state laws on exemptions may vary.)

Some of the exemptions below have tighter restrictions with the latest federal updates. For example, there is now a minimum wattage for infrared heat lamps that will result in some lower wattage heat lamps being discontinued without equivalent wattage replacements. For more detail on exemptions, you can review this link.

The exemptions include:

Appliance lamps
Black light lamps
Bug lamps
Silver bowl lamps
Colored lamps
G shape lamps with a diameter of 5 inches or more
General service fluorescent lamps
Sign service lamps
High intensity discharge lamps
Infrared lamps
J, JC, JCD, JCS, JCV, JCX, JD, JS, and JT shape lamps that do not have Edison screw bases
Showcase lamps
Lamps that have a wedge base or prefocus base
Left-hand thread lamps
Marine lamps
Specialty MR lamps
Marine signal service lamps
Mine service lamps
Plant light lamps
Traffic signal lamps
Other fluorescent lamps R20 short lamps
MR shape lamps that:
have a first number symbol equal to 16 (diameter equal to 2 inches) as defined in ANSI C79.1– 2002
operate at 12 volts, and
have a lumen output greater than or equal to 800
Reflector lamps that have a first number symbol less than 16 (diameter less than 2 inches) as defined in ANSIC79.1–2002, and that do not have E26/E24, E26d, E26/50x39, E26/53x39, E29/2 S shape or G shape lamps that have a first number symbol less than or equal to 12.5 (diameter less than or equal to 1.5625 inches) as defined in ANSI C79.1-2002
T-shape lamps that have a first number symbol less than or equal to 8 (diameter less than or equal to 1 inch), nominal overall length less than 12 inches, and that are not compact fluorescent lamps"

It seems there should have been an exemption for historic preservation replicas, although the argument can be made the with the special features we've discussed, Street Railway lamps are NOT General Service lamps. Does anyone have a friendly congressman or senator willing to slip an exemption into the next omnibus spending bill?

And even if exempted, is the market large enough to gear up production?

My guess would be that if a manufacturer has the tooling and materials are available, then the answer could be “yes”. Not on market size, but on the size of the production run. There’s a minimum piece count where the costs to produce and inventory makes it profitable and not cost and price prohibitive. What that quantity is, who knows? Might be a hundred, could be thousands.

Many years ago, a concerted effort was made to compile a consortium of streetcar museums to allow for a "last run" of a production lot of bamboo rattan seat covering fabric from the last mill capable of making it before it disposed of the tooling since it was no longer a commercially viable product. Perhaps something similar can be done for specialized lamps - provided the quantities of each kind are adequate for support.

And it's on:

https://www.aol.com/know-ban-incandesce ... 00264.html

The ban pretty much applies to general lighting. I haven’t dug into it yet but I don’t think bulbs such as PAR56 loco bulbs would be included. For steam era headlights, those bulbs may not be banned, or might be - dunno, but the fact remains that no one manufactures them at this time that I’m aware of.