Soviet PBP-1 sight optional for older planes?

[Jorge_S]

Good afternoon,

new Soviet planes (Yak-9, Yak-9T) come with iron sights; with the reflector sight PBP-1 as optional

 

Is there a plan to retrofit older soviet planes (Yak-1, Lagg-3, La-5, I-16) with iron sights?

 

as far as I understand it was during the times of BOM, BOS where equipment like reflector sights was scarce; so it seems a bit odd that the standard sight is reflector then and not when the more modern planes arrive