I see that the lithium here, have a broadened self-reserved profile. I never seen it in that profile on a general lighting MH lamp and in a photo generally. I'm wondering if this lithium is an intentional dosage or impurity, as it is so huge.
My Osram HQI-TS 70W/WDL Excellence in my track light, also have lithium, but not as broadened as like here.
Interesting that the secondary orange line of the lithium, didn't broadened as well, as it is strong even in the spectrum of my lamp.
Wondering why it have only one wing like the sodium line. Is the mercury interacts with other elements beside sodium?

Oh no this is a very big dose of lithium on purpose. These are sodium-scandium-lithium iodide metal halide lamps. https://patents.google.com/patent/CA1102390A/en

I have been getting other CMH spectra which I'm working to upload soon. None show this type of lithium dose, certainly not the HQI-TS WDL or NDL, which are fantastic little lamps.

I'm not sure of the physical mechanism (may have been answered somewhere in LG by medved) but the broadening shift is to lower energy (longer wavelengths) which is also common to thallium broadening as well as the sodium 589/590 shift. Btw, HPS depleted lamps also show this redder wing - the left (yellow) wing conspicuously missing.

Here is a spectrum of my Osram HQI-TS/WDL Excellence. I think you have older generation of this lamp, which didn't contained lithium.
I thought British Thorn made patents for a Na-Sc-Li lamp: http://www.lamptech.co.uk/Spec%20Sheets/D%20MHQ%20Thorn%20MBIFHS250.htm
Update: Here are better pictures of the spectrum of my lamp. My camera have though time to show the lithium lines, so I had to capture the spectrum again overexposed.

You have a good memory dor! The referenced Canadian patent is actually the same as the UK one on my page. However in Canada at that time Thorn filed its patents under the name of EMI Group, with whom it later merged to form Thorn EMI / Electrical & Musical Industries.

Thorn and Sylvania had a joint patent interchange agreement from 1946 until 1990 and had free use of each others patents and developments. I have since learned that other makers produced Lithium-doped metal halide lamps before this patent, but apparently not with a mixture that limited the negative impact on life.