Fixing Linux Mint 17.3 for Meltdown and Spectre

[hellwoodfire]

Hello everyone, I use Linux Mint 17.3 so I am really interested about knowing about you guys, Mint 17.3 users, how you successfully or not applied the kernel patches just released on January 10th 2018.
So, please share all your stories about applying the security updates!
I any little detail or trick that you would you have liked to know before performing the operation ?

Here is my own story:
I have 2 computers on Linux Mint 17.3.
I did not apply the kernel security updates because I am confused!
I am confused because my 2 computers use 2 specific kernels which are not listed in the Security notice ( https://blog.linuxmint.com/?p=3496 ).

* 4.2.0-19-generic (because it worked better with my nvidia GTX 750 Ti)
Motherboard: Gigabytes H97M-D3H
CPU: Intel(R) Core(TM) i5-4590 CPU @ 3.30GHz

* 3.19.0-32-generic (because it was the default kernel for Mint 17.3)
Motherboard: MSI H81M-P33
CPU: Intel Pentium CPU G3220 @ 3.00GHz

As you can see, non of my "Meltdown and Spectre" updatable because they are not in the list. The following versions were patched:
3.13 series (Linux Mint 17 LTS): patched in 3.13.0-139
3.16 series (LMDE): patched in 3.16.51-3+deb8u1
4.4 series (Linux Mint 17 HWE and Linux Mint 18 LTS): patched in 4.4.0-108
4.13 series (Linux Mint 18 HWE): patched in 4.13.0-25

Which kernel should I use ?
Should I switch to the required kernel version before applying the security update ?
Should I wait until my own kernel version will be updated ?

[Spearmint2]

viewtopic.php?f=208&t=261394&p=1412677#p1412677