Seeking cistern lever for 70's toilet

I have an Armitage Shanks toilet that must have been installed in the 1970's.
The flushing handle/bearing has worn but I've "fixed" it with some plastic strip and it seems to work ok for now.
I'd like to replace the handle assembly but I'm having difficulty finding one that would definately do the job.

Requirements are:

Square bar needs to extend 15.5 cm from outside edge of cistern
Cistern side thickness 1.0 - 1.2 cm
2.14 cm cistern hole diameter (on the side)
1.878 cm across existing thread of bearing (3/4 in?)
(Existing square bar 0.96 cm (3/8 in?) across)

Suggestions anyone?

Thanks,

Steve

 

A photo may help. So the cistern handle is side mounted?

 

or front mounted Lots of variations in the 70's. ( including colours of ceramics )

 

Yes, the lever is on the side (as mentioned by hole diameter).

 

Yes I thought so, just checking.

Have you tried any of these?

https://www.amazon.co.uk/Ideal-Stan...M2FWK3AH7HT&psc=1&refRID=KXV7DWSQ2M2FWK3AH7HT

https://fastpart-spares.co.uk/searc...CH=Handle&LEVEL3=TOILET~CISTERN~SPARES&Page=1

 

A picture, hope it helps.
(also hope I've done it right - not that used to foruming!)

 

The wickes 216980 may be close. The length is specd at 17.3 cm. As with a lot of this sort of thing its hard to tell from that and the picture.
Thanks JimCrow (and all).