Turn fridge back to a freezer query

[Marsay]

hi guys new to forum and just after a bit of advise i have customer who has a 2mtrx3mtrx2.5high cold room which was originaly a freezer (so he says) although there is evidense of it been a freezer i.e heaters and thershold heater the evaporator is a searle ks20-4 and is currently running as a fridge,he now wants it back to a freezer there is no details on condensing unit but is a unite hermetique on r134a also r134a ex valve now the question
1 could i just replace compressor for a lbp r404a if so what hp-cc
2 would i need to change full condensing unit if so any what you would reccomend
3 anything else apart from valve refrigerant and condensing unit

oh the freezer will be storing paultry and should be entering chilled (fresh)

ps sorry about grammer and spelling

thanx danny

[monkey spanners]

Get the duty sized by the wholesalers, then get them to compare to what you got. Then you'll know if it could be made to work!