Spare parts alternatives (GP320 to GP360 upgrade)

[Shuttle]

Due to previous events, I have access to a few waris (not lazarus) GP320 VHF:s.
Also, I have access to a few GP340:s.
And due to a more recent event, I have a GP360 with a busted rf board - but a decent case and a need for a radio with display.
The busted GP360 has the 8486062B16 PCB, which according to the detailed service manual is probably of the latest "waris" boards, before "lazarus" came along.
Waris here is with the orange battery seal, and Lazarus with the blue seal.
I might be completely wrong here, so please do correct me.

Now, the GP340 and GP320 both lack the RTC-circuits as well as the on board lithium battery with its charging circuitry and contacts.
The GP320 is a tad easier, as there is no channel switch, a new one just needs to be welded, as well as a 40pin flex connector and two tactical switches.
As for the GP340, the flex connector is there, as well as the tactical switches - but the channel switch needs to be replaced with a continuously rotating switch.

The most obvious parts; the flex connector, channel switch and tactical switches are easily available as common spares.

A preliminary report from the local shop gave me that the resistors, capacitors and other smaller parts under the main controller shield might be unavailable.
Hence, I would ask if anyone knows what parts could be used as replacements for the following components:

C434 2113928N01 0.1uF, 10% (not used in GP640/GP240)
C436 2113743N34 22pF (not used in GP640/GP240)
C437 2113743N34 22pF (not used in GP640/GP240)
FL401 4870368G02 Real Time Clock Oscialltor XTAL (not used in GP640/GP240)
PB501 4080523Z01 Tactile, Pushbutton
Q416 4809579E18 Mosfet P-channel (not used in GP640/GP240) TP0101T
R419 0662057M67 510 (not used in GP640/GP240)
R420 0662057B46 10M (not used in GP640/GP240)
R426 0662057N35 330K (not used in GP640/GP240)
R461 0662057M56 180 (not used in GP640/GP240)
R462 0662057M98 10k (not used in GP640/GP240)
U410 5102463J57 REG 3.3V, ILC7062CM-33

For the caps and resistors I would need to know type and size.
The regulator could easily be replaced by comparing spec sheets.

Also, if someone has knowledge what the RTC circuit is good for, is it necessary and what functionalities will be lost without it, please do tell.

And as a last note, this radio is for amateur use. If I'll find a replacement board or radio for less than EUR130 (including shipping) I would like to take that route.
Other than that, this is mostly to learn.

Best regards,
Martin,
73 de OH2FTU