It is not clear from your quarries as to what age related senescence parameters you are interested to analyses using mice? As you know that the senescence acts as a central hallmark of aging, which is driven by telomere damage, epigenetic dysregulation, DNA damage, and mitochondrial dysfunction, oxidative stress etc. Several of these drivers of damage can induce senescence.
The IHC and WB are the two methods that you can use to analyze the actual cellular changes (IHC) or protein changes (WB). I would suggest that you first identify the few important age related senescence parameters and then look for appropriate methods (techniques) by which you can easily and authentically analyze the the parameters of you interest to address age related senescence.
For various parameters of age related senescence and methods that might help you to plan your experiments or techniques are given below:
Senescence and aging: Causes, consequences, and therapeutic avenues. J Cell Biol. 2018 Jan 2; 217(1): 65–77.
Article Senescence and aging: Causes, consequences, and therapeutic avenues
Techniques for Analysis of Biological Aging. Methods Mol Biol. 2007; 371: 1–7.
Article Techniques for Analysis of Biological Aging
Cellular senescence in age-related disorders. Volume 226, December 2020, Pages 96-104.
Usually, the first experiment that should be done is Senescence-associated beta Galactosidase assay
doi:10.1038/nprot.2009.191
This is the most widely used biomarker for cellular senescence (publishing-wise, it should be the first figure to show among senescence markers verified). Senescent cells are known to have high lysosomal content, this method detects Beta-galactosidase activity at suboptimal pH (pH=6).