Late 2008 MacBook Pro (MB470LL/A) - Keeping it going - Help!

Looking for opinions/help on how to keep MB470LL/A going 8 years on, as physically, it still looks brand new and current in its styling AND I can't afford a new one at all. I still use Photoshop CS5 and Aperture 3 to edit Photographs mainly as everything else I do on my smartphone these days.

The optical drive is broken so not sure whether to buy a second hand one, which I could install myself.

The battery is a third party one from Amazon £35 and doesn't last more than twenty minutes. It can cut out when it feels like it and when I return to my Mac after a few days and the power has been pulled out, it takes ages to wake up, sometimes it's gone into deep sleep mode so makes a fake startup sound and shows the progress bar dimmed out. But even after it has gone through the wake-up process and the password box comes up, it won't let me type and instead the screen blacks out and the keyboard is unresponsive for around 30secs to a minute before coming back on, and spending several more seconds before letting me type my password in. It's infuriating really.

I also need a new power lead really as that is third party and very dodgy getting hot and making a clicking sound at the transformer with sometimes an electric shock type static feeling when you touch the metal chassis.

It has 8GB RAM from Crucial UK and a hybrid SSD/Harddrive 750GB. I wonder what the culprit is?

I'm still running 10.8.5 and would like to upgrade as Google Chrome is no longer supported or anything much.

As it has an express card port, I can install my SD card reader or USB 3 ports and so it is still proving up to date there. I also like that I can change the battery myself, although finding a replacement that will actually let me take this portable again seems impossible as Amazon reviews are all fake these days.

Has anyone one they can recommend? I'm in the UK and don't really want to order from the US as am worried about customs charges.

Here are some stats from my About Mac:

Hardware Overview:

Model Name: MacBook Pro

Model Identifier: MacBookPro5,1

Processor Name: Intel Core 2 Duo

Processor Speed: 2.4 GHz

Number of Processors: 1

Total Number of Cores: 2

L2 Cache: 3 MB

Memory: 8 GB

Bus Speed: 1.07 GHz

Boot ROM Version: MBP51.007E.B06

SMC Version (system): 1.33f8

Serial Number (system): W884114L1G0

Hardware UUID: C14E44B5-FF01-5896-B154-F14C0F74E29C

Sudden Motion Sensor:

State: Enabled

Battery Information:

Model Information:

Serial Number:

Manufacturer: topping-battery

Device Name: ASMB013

Pack Lot Code: 3230

PCB Lot Code: 30db

Firmware Version: ddae

Hardware Revision: dac2

Cell Revision: 2b39

Charge Information:

Charge Remaining (mAh): 4887

Fully Charged: No

Charging: Yes

Full Charge Capacity (mAh): 4908

Health Information:

Cycle Count: 205

Condition: Normal

Battery Installed: Yes

Amperage (mA): 271

Voltage (mV): 12587

System Power Settings:

AC Power:

System Sleep Timer (Minutes): 0

Disk Sleep Timer (Minutes): 0

Display Sleep Timer (Minutes): 0

Automatic Restart on Power Loss: No

Wake on AC Change: No

Wake on Clamshell Open: Yes

Wake on LAN: No

Current Power Source: Yes

Display Sleep Uses Dim: Yes

GPUSwitch: 2

PrioritizeNetworkReachabilityOverSleep: 0

Battery Power:

System Sleep Timer (Minutes): 25

Disk Sleep Timer (Minutes): 10

Display Sleep Timer (Minutes): 10

Wake on AC Change: No

Wake on Clamshell Open: Yes

Display Sleep Uses Dim: Yes

GPUSwitch: 2

Reduce Brightness: Yes

Hardware Configuration:

UPS Installed: No

AC Charger Information:

Connected: Yes

ID: 0x0100

Wattage (W): 60

Revision: 0x0000

Family: 0x00ba

Serial Number: 0x00bd7fdc

Charging: Yes

HardDrive 750GB:

Available: 9.99 GB (9,989,115,904 bytes)

Capacity: 749.3 GB (749,296,615,424 bytes)

Mount Point: /

File System: Journaled HFS+

Writable: Yes

Ignore Ownership: No

BSD Name: disk0s2

Volume UUID: C4D6B80A-3A1E-316C-8A1D-076685B34A33

Physical Drive:

Media Name: ST750LX003-1AC154 Media

Medium Type: Rotational

Protocol: SATA

Internal: Yes

Partition Map Type: GPT (GUID Partition Table)

S.M.A.R.T. Status: Verified

MATSHITA DVD-R UJ-868:

Firmware Revision: KB19

Interconnect: ATAPI

Burn Support: Yes (Apple Shipping Drive)

Cache: 2048 KB

Reads DVD: Yes

CD-Write: -R, -RW

DVD-Write: -R, -R DL, -RW, +R, +R DL, +RW

Write Strategies: CD-TAO, CD-SAO, DVD-DAO

Media: To show the available burn speeds, insert a disc and choose File > Refresh Information

Memory Slots:

ECC: Disabled

BANK 0/DIMM0:

Size: 4 GB

Type: DDR3

Speed: 1067 MHz

Status: OK

Manufacturer: 0x0000

Part Number: 0x00000000000030434C372D34474253510000

Serial Number: 0x00000000

BANK 0/DIMM1:

Size: 4 GB

Type: DDR3

Speed: 1067 MHz

Status: OK

Manufacturer: 0x0000

Part Number: 0x00000000000030434C372D34474253510000

Serial Number: 0x00000000