You really need legal advice on this. It’s more complicated because you say his pension is already in payment. There’s some case law (it may be outdated now!) that actually treated a pension in payment not as an asset.
His 2 pensions might be 2 pots of money that he’s drawing down. But you talk about a monthly payment, so he may have bought an annuity. Different annuity types have different rules about pension sharing options on divorce.
Legal fees (according to a quick google, so you know, see a proper qualified person not a random like me on line who had a PSO and is interested in pensions!) are higher for pension sharing work when in payment as they’re more complicated.
Would you consider offsetting? That’s where you take a bigger percentage of other equity (the house?) but leave his pension to him. This might be simpler and suit you better.
But you really need to talk to a solicitor about it. 50/50 may be a common start point, but I’d be arguing that you’re younger, have a longer life expectancy (at least based on your gender), but both of you are beyond an age where you could reasonably expect to work again - so, I’d be arguing for more on that based. As a start point I’d take your statistical life expectancy less current age, and split proportional to the years.
If I was looking for a solicitor, I would specifically ask if they had experience in divorce during retirement, it’s not that common.
What role you played in the business and home isn’t relevant, long marriage, joint assets.
Have you checked your state pension entitlement, that you have the full number of qualify years for a full pension? If not, I’d blame that on your joint choices and argue for an additional percentage to balance that.
Good luck! x