Has Russia even pressed older MIG and SU models back into service? They are one of the few pieces of equipment that haven't suffered catastrophic losses when compared to MBTs and IFVs.
Depends on what you consider "old".
Both side are/were using Su-24, introduced 1974, for air support as it has a big combat load; ukraine because they didn't have anything better, Russia because they were cheaper and more plentiful at the start of the war than Su-34s. The changing threat environment has gotten Russia to largely move away from the Su-24 except as an air-launched cruise missile platform.
Poorly sourced wonking has said a lot of the russian Su-24 airframes are pretty well fucked due to stress from trying into the SAM zone.
Su-25 is also heavily used by both sides introduced in 1975, but those airframes are holding up better.
For MiGs, the oldest is the Mig-29 introduced in 1983. There isn't a lot to say here as they are mostly interceptors vs. Sukhoi's multi-role and they haven't been really mixed up in the shit after the first couple of weeks, mostly flying CAP and using look-down radar to lob stand-off missiles at Ukrainian jets. They have seen a number of losses just due to Slavic maintenance schedules (aka none) and a handful of humiliating shootdowns from pilots not appreciating a change in the airspace.
And Tu-95 bombers (introduced 1956) are also used for cruise missiles, but they are used at such range and altitude they only threat is drones when they are on the ground.
Something something An-50 and Il-76, also from the early 80s.
And just for transparency, the F-16 was introduced in 1978 but has seen significant upgrades since then.
edit: forgot to tie that all together:
Russia isn't seeing air-to-air combat, and all areas where close air support would be needed are completely rotten with SAMs; Anything older than an Su-24 is just going to be SAM fodder, and even that's pushing it. The Su-25 is only able to keep in the fight because it was designed to fly under SAM radar.
The older planes would have issues integrating modern weapons as well; the Su-25 is mostly just doing rocket lobs.
Russia has something like 500 Mig-29s, granted a lot of those are mothballed (read: utterly fucked and need a rebuild) but it is very unlikely they will be in a situation where even if they have some Mig-25s or 21s lying around that they will be pressing them into service.
I know never say never, but Russia would likely
poison Putin KGB style tap out on Ukraine before their airwings reach such a dire situation.
You see those old deep coldwar planes active in two cases:
A) as a bomber/attack craft against insurgents as lack of effective AA means they are able to operate nearly uncontested.
B) as an AA missile platform, because it just needs to lock and launch.
A isn't DEFINITELY not the case for the Ukrainian theater, and B is currently not needed by Russia.
Afaik only those MiGs and SUs currently in use are having their boneyard brethren being either cannibalize for parts or for the fortunate few made flyable again. Russia is a terrible place to boneyard aircraft if the intent to maybe have them flyable again in case of emergency.
Ukraine is also in the same boat as the only they're pulling out of their boneyards are what they're using right now.
Ukraine is also getting boneyard parts from former WARPACT/WARPACT supplied countries. Lots of former SSRs taking advantage of the incredible deals on trade-in.
I thought so too.
Other outlets are repeating those numbers as well, but I figure they're highly optimistic. Even if there happened to be a huge subsurface hive/barracks literally packed with norks, I'd say 500 is still a bit much.
My assumption is Journiggers repeating other journolies, and start of the telephone game getting something wrong and never bothered to follow up or double check because lol a modern journigger doing research or checking statements instead of mashing the "submit" button as soon as they have stopped squiting out text.
i.e. The NK General who got
whacked INJURED BUT YOU CAN'T INTERVIEW HIM RIGHT NOW may have been "leading a unit of 500 soldiers", the wrecked base capable of holding 500 soldiers, or 500 NK & Russian soldiers in total being injured & killed.