Hello Ivan,
It may be possible to fix the bellset to the base of your 232L if you want, this is commonly known as a "King Pyramid" - it depends on the type of fixing screws that have been used to hold the bellset cover to it's base. That way you could use one of the short reproduction braided cords that are available to connect your 232L to the bellset.
A good write-up with photographs on how to do this is available here:
http://www.britishtelephones.com/pyramidandbell.htm
How to wire the 232L to the bellset and then wire your modern line cord to the bellset can be found here about a quarter of the way down the page:
http://www.britishtelephones.com/pstconv1.htm#232
Regards, Lee.