I don't know about Boler
space available for a fridge
, but maybe you could check a posting I did about replacement of a dying RM211 (very similar to the one you bought) with a used but recent Norcold 323. Have a look at my old posting, in case it inspires you. Installing a 21" deep fridge into a 19" space on a Trillium 4500
You must know that absorption refrigerators (gas, 12V, 110V) require to be LEVEL in order to prevent overheating. Overheating will damage the chemical mix of water, hydrogen gas and ammonia, so it won't be as efficient again. Extended periods without use sometimes cause the ammonia to form crystals which can further interfere with gravity circulation. If you are told that reversing a fridge has cured the problem, (may dislodge the obstruction) it only means that the refrigerant is in poor shape and that the dying fridge is on palliative care. (see The RV Doctor: RV Absorption Refrigeration Basics
Consequently, you can imagine that the older the fridge, the higher the risk of buying such used fridge. You can add that if the shell is damaged or the door seal is not perfectly airtight, such fridge will have a hard time to keep your stuff cool in a hot summer day. https://en.wikipedia.org/wiki/Absorption_refrigerator
I would suggest you check the space you have in your RV compared to what's available in terms of sizes as used fridge with a warranty from a RV dealer (what I did). It ended up being half the price of a new one and it works perfectly fine. I would not buy anything much older than 5 years old.
Finally, in order to work properly regardless of the amount of gas left or hot/cold weather, an absorption fridge requires a constant LP gas pressure that can only be provided from a two stage gas regulator. Some old RV often get equipped with a single stage regulator https://en.wikipedia.org/wiki/Pressure_regulator
I hope this will help you make a better deal next time.
Good luck !