First, you have done well by recognising that you need to consider your personal finances.
I understand that:
(1) You can finance the bigger house from partner’s house sale, and have no other ‘big spends’ to come
(2) You will retire within 6 years and will need your savings to finance living
(3) You have saved into a private pension: consider who runs that, can you draw from Age 55, how much you will draw from it, etc.
I am not clear (and need not be) how much of your living expenses at Age 55 will be taken from your pension. Do make sure you understand the principles of 25% lump sum, taxation of the rest, etc. if your pension will subsist for many years then consider how you will invest it - what funds etc.You could engage a good IFA.
You indicate that the main source of money in retirement is your non-pension savings. Given your investment period starts within only 5-6 years be careful; but if your savings will subsist throughout your retirement - 30 year plus? - you need to consider Equities..
You need a plan projecting your future income, the sources of that income, and expenses. Then you can assess how much, and when, you will need those savings. From that you can devise an investment plan.
You mention VUSA and American Equities. Ouch. Before this evaluate your investment plan, asset allocation, and how much in Equities. At present the US stock market is horribly over priced. Look at Europe and, some would say, the UK.
Standing back, you may benefit from advice from an IFA. Find a good one from personal recommendation. Set out clearly what you want, and do not want. Agree a fixed fee or hourly rate with estimate. Do not get suckered in to paying x% of your investments every year.
I wish you well but plan first and be careful.